Wikipedia:Manual of Style/Military history

This is a style guide for military history articles. It is intended to provide editors working on such articles with recommendations in relation to article naming conventions, formatting and presentation, template use, and categories. Advice on notability and content in relation to military history articles can be found at WikiProject Military history/Notability guide and WikiProject Military history/Content guide.

Application
Many articles may deal extensively, but not exclusively with military-related topics. When in doubt, or when there is no clear consensus, defer to WP:MOS. As a general rule, this guidance should only be used where it is helpful, and should not be used as grounds for extensive disruptive renovations of existing articles.

Biographies
Consensus to follow this guidance on biographies of living or deceased persons should be based primarily on the prominence of military service in the WP:NOTABILITY of the individual. For example, an article on a Medal of Honor or Victoria Cross recipient, who is notable only for their military service, should most likely follow this guidance. An article on an individual, such as Elvis Presley, who would be notable had they never served in the military, most likely should not. Biographies of civilians, such as Marise Payne or Ash Carter, who are notable in large part for military-related reasons, but who themselves did not serve in uniform, should generally not follow this guidance.

Biographies of living people (BLPs) and those of people who have recently died must follow Wikipedia's BLP policy.

Events
An article should generally be placed at the most common name used to refer to the event (such as Battle of Gettysburg, siege of Leningrad, attack on Pearl Harbor, or Doolittle Raid). If there is no common name, the name should be a descriptive geographic term such as "battle of X" or "siege of Y", where X and Y are the locations of the operations; see also the section on capitalization. Non-neutral terms such as "attack", "slaughter", "massacre", "raid", "liberation", or "fall" should be used with care.

If disambiguation is needed, the year may be added in parentheses (as in Battle of Salamis in Cyprus (306 BC)). Multiple battles at the same place in the same year should be called "First", "Second", and so forth (as in First Battle of Zurich and Second Battle of Zurich). Alternatively, the month of the battle may be used as a disambiguation (as in invasion of Tulagi (May 1942)); follow usage in reliable sources.

Orders of battle
Titles for stand-alone list articles comprising orders of battle should generally be formulated as:
 * Name of military event/organisation order of battle

For the common case where the orders of battle for a military event are split into separate list articles by belligerent or opposing forces, then the naming conventions for split lists apply, and the format becomes:
 * Name of military event order of battle: Belligerent

as in Invasion of Yugoslavia order of battle: Axis or Battle of Raymond order of battle: Confederate. The military event should include any necessary disambiguation in the same way as the article about the event does; for example Raqqa campaign (2016–2017) order of battle. The parent list name should exist as a List of lists with links to the split lists. Redirects should also be created to shorter forms of the title that are likely to be searched, such as Gettysburg order of battle and Gettysburg order of battle: Union.

Operational codenames
Operational codenames generally make poor titles, as the codename gives no indication of when or where the action took place and only represents one side's planning (potentially leading writers to focus on that side's point of view). It is better to use an appropriate geographical name for the article, creating a redirect from the operational name, for all but the most well-known operations (such as Operation Barbarossa), or for military actions that were never carried out (such as Operation Green).

Style of operation names
References to operations are to be in accordance with the following examples, noting the use of capitals in the examples.


 * The Axis plan, Operation Xyz, was a proposal for the invasion of ...
 * The Xyz operation called for a combined overland and amphibious ....
 * Troop movements in preparation for Xyz commenced in ...

Operation Xyz is a compound proper noun and capitalised accordingly. No emphasis, such as quote marks, boldface (see special case, below) or italics are added even in the case of foreign words such as the following. A distinction is made when the correct foreign name or a translation is being offered.


 * Operation Rimau
 * Operation Barbarossa (German: Fall Barbarossa, literally "Case Barbarossa")
 * Operation Wunderland (German: Unternehmen Wunderland)

Links to articles in a campaign box are to be italicised but are not preceded by the word 'Operation' – i.e. "Cartwheel" only. Refer to the example in the Solomon Island campaign box for an actual example.

Boldface is used to highlight the first occurrence of the title word in the lead section in accordance with MOS format of the first sentence (lead). It is also used (almost exclusively in the lead) when the operation name is a redirect to a page about the associated battle or an alternative (synonymous or nearly synonymous) name for the operation as in the examples that follow [see also MOS:BOLD, particularly the section on Other uses (of boldface)]:


 * For the article, Normandy landings, the lead opens: Normandy landings (codenamed Operation Neptune) were the landing operations on 6 June 1944 ...
 * For the article, Operation Torch, the lead opens: Operation Torch (initially called Operation Gymnast) was the ...

Tanks
For the sake of uniformity, ease of understanding and clarity, all articles documenting tanks should include "tank" as a part of its title, generally appended at the end. For instance:


 * The Heavy Tank M6 article is titled M6 heavy tank.
 * The Type 1 medium tank Chi-He (also known as Type 1 Chi-He) is titled Type 1 Chi-He medium tank and so on...

Units, formations, and bases
An article about a unit, formation, or base should be placed at "Name" or if "Name" is ambiguous at "Name (disambiguating term)". The name should generally be either the official name used by the armed forces to which the unit or base belongs; or, in cases where no relevant formal name exists or where a formal name is not commonly employed by historians, the most common name used in historical literature.

A name originally in a language other than English should be adapted by translating common terms (such as designations of size and type) and transliterating the remainder of the name. The choice of which components of the name are to be translated (and how) should follow the conventions employed by reputable historical works on the topic; some collected recommendations for specific terms are maintained by the relevant national task forces. The original name should be provided in the first sentence of the article, following the translated name; for example: The 3rd Mountain Division (3. Gebirgs-Division) was... or Boden Fortress (Swedish: Bodens fästning) is....

Names should generally follow the stylistic conventions used by the service or country of origin. For example, while US and British usage has spelled-out numerals for army-level formations and Roman numerals for corps, editors writing about different countries should follow those countries' normal usages; thus, "3. Panzer Armee" becomes "3rd Panzer Army", and "18-ya Armiya" becomes "18th Army".

For units whose name is ambiguous on Wikipedia, the disambiguating term should be the common name of the country whose armed forces the unit belongs to (as in 4th Infantry Division (United Kingdom)), or, if such usage is still ambiguous (or where the unit does not serve a country), the name of the service branch to which the unit belongs (as in 1st Panzer Division (Wehrmacht)). The disambiguating term is not necessary in cases where the name is unambiguous (as in The Queen's Own Rifles of Canada or Preobrazhensky regiment).

In cases where a unit's name can reasonably be expected to be used by multiple armed forces—particularly in the case of numerical unit designations—the units should generally be preemptively disambiguated when the article is created, without waiting for the appearance of a second article on an identically named unit. If this is done, the non-disambiguated version of the unit name should be created as a disambiguation page (or a redirect to the disambiguated version).

For bases whose name is ambiguous on Wikipedia, the disambiguating term should be the region, province, state, or territory in which the base or fortress is located; for example, "Fort Lyon (Virginia)" and "Fort Lyon (Colorado)". The disambiguating is not necessary in cases where the name is unique to a single fortress or base.

When a unit or base has had multiple names over the course of its existence, the title should generally be the last name used; however, exceptions can be made in cases where the subject is clearly more commonly known by one of the previous names.

Root pages for the armed forces of a state are named, if the official name is known, by the official name's English translation (for example, "Australian Defence Force"). If the native language name is most commonly used, this should be kept (for example, "Bundeswehr"). Other national armed forces are only provisionally located at "Military of X", and should be renamed to the translation of the official name when available. Alternately, articles can be renamed if there is consensus over how the armed forces in question are normally referred to in common usage (for example, "United States Armed Forces").

Category names
A number of naming conventions exist specifically for category names; most of these are used to ensure consistent naming among all the sub-categories of a particular category.


 * "X by country" : In most cases, sub-categories of a category named "X by country" take names of the form "X of [the] Y", where Y is the most common name of the country in question. For example:
 * Category:Military by country → "Military of [the] Y" (as in Category:Military of Russia)
 * Category:Military equipment by country → "Military equipment of [the] Y" (as in Category:Military equipment of France)
 * Category:Military history by country → "Military history of [the] Y" (as in Category:Military history of the United States)
 * Category:Military units and formations by country → "Military units and formations of [the] Y" (as in Category:Military units and formations of the United Kingdom)
 * Category:Weapons by country → "Weapons of [the] Y" (as in Category:Weapons of Italy)
 * The subsidiary "by branch" categories for topics such as military units or personnel follow the same convention, with the full branch name replacing the country name (as in Category:Military units and formations of the United States Army).
 * Categories classifying military conflicts and operations by country take names of the form "X involving [the] Y" instead:
 * Category:Battles by country → "Battles involving [the] Y" (as in Category:Battles involving France)
 * Category:Military campaigns by country → "Military campaigns involving [the] Y" (as in Category:Military campaigns involving the United States)
 * Category:Military operations by country → "Military operations involving [the] Y" (as in Category:Military operations involving Germany)
 * Category:Sieges by country → "Sieges involving [the] Y" (as in Category:Sieges involving France)
 * Category:Wars by country → "Wars involving [the] Y" (as in Category:Wars involving the Ottoman Empire)


 * "X by period" : In most cases, sub-categories of a category named "X by period" take names of the form "X of the Y period", where Y is the name of the period of warfare in question. For example:
 * Category:Battles by period → "Battles of the Y period" (as in Category:Battles of the Early Modern period)
 * Category:Military units and formations by period → "Military units and formations of the Y period" (as in Category:Military units and formations of the Early Modern period)


 * "X by war" : In most cases, sub-categories of a category named "X by war" take names of the form "X of [the] Y", where Y is the most common name of the war in question. For example:
 * Category:Battles by war → "Battles of [the] Y" or "Battles and operations of [the] Y" (as in Category:Battles of the Hundred Years' War)
 * Category:Campaigns by war → "Campaigns of [the] Y" or "Theaters and campaigns of [the] Y" (as in Category:Theaters and campaigns of World War II)
 * Category:Military personnel by war → "Military personnel of [the] Y" (as in Category:Military personnel of World War I)
 * Category:Military units and formations by war → "Military units and formations of [the] Y" (as in Category:Military units and formations of the American Civil War)
 * Category:People by war → "People of [the] Y" (as in Category:People of the Hundred Years' War)


 * "X by size" : This category tree is used primarily for military units and formations; sub-categories take the name "Y", where Y is the size in question (as in Category:Military units and formations by size → Category:Regiments, Category:Corps, and so forth).
 * "X by type" : In most cases, sub-categories of a category named "X by type" take names of the form "Y X", where Y describes the type in question. For example:
 * Category:Battles by type → "Y battles" (as in Category:Naval battles)
 * Category:Military units and formations by type → "Y units and formations" (as in Category:Airborne units and formations)
 * Note that this form of category tree tends to exhibit more varied naming than the others. For example, Category:Battles by type also includes the non-standard Category:Sieges (since "Siege battles" would be a cumbersome name).


 * Intersection categories : The names of intersection categories generally follow the same conventions as above, with the name components of their parent categories placed in normal grammatical order (usually with period/war designations given after country/branch ones). This produces, for example, "Naval battles of the Early Modern period" (type and period) and "Airborne regiments of the United States Army in World War II" (type, size, branch, and war).

Capitalization
The general rule from MOS:CAPS is that wherever a military term is an accepted proper name, as evidenced by consistent capitalization in reliable sources, it should be capitalized in Wikipedia. Where there is uncertainty as to whether a term is a proper name, consensus should be reached on the talk page; the MOS:CAPS default is to use lower case, unless and until evidence of consistent capitalization in the sources is presented.

When using a numerical model designation, the word following the designation should be left uncapitalized (for example, "M16 rifle" or "M109 howitzer") unless it is a proper noun.

Dates
Existing articles related to military history should follow MOS:DATERET as a default, and extensive efforts should not be undertaken to comply with this guidance for its own sake, unless there is strong consensus for the change.

Per MOS:DATETIES, articles on subjects predominately related to militaries or military history should use the standard format adopted by the United Nations: DD Month YYYY (or D Month YYYY). This includes spaces and excludes hyphens or commas. In cases where the day is a single digit, a leading 0 should be omitted. For example:


 * 1 January 1900 and not 1-January-1900; 1 January, 1900; 1January1900 or 1, January 1900
 * 1 January 1900 and not 01 January 1900

All articles should follow MOS:DATEUNIFY, and should not mix date formats.

En dashes
The Manual of Style specifies that an en dash rather than a hyphen should be used. Where there are internal spaces within one or both items, the en dash should be spaced on both sides. Examples:
 * 1968–1970, not the hyphenated 1968-1970
 * May–August 1944
 * 3 June – 15 August 1914; not 3 June - 15 August 1914
 * 12–14 September 1943

Minimal repetition
Consider expressing date ranges without repetition; thus:
 * January–March 1968, not January 1968 – March 1968
 * 3–4 November 1951 not 3 November 1951 – 4 November 1951; nor even 3 November – 4 November 1951

Closing item
It is preferred that the closing year in a year range be four digits rather than two, per MOS:DATERANGE:
 * The second phase (2004–2006), rather than The second phase (2004–06)

Flag icons
In general, the use of flag icons is not recommended; neither, however, is it prohibited. When deciding whether flag icons are appropriate in a particular context, consider:
 * Do the icons convey useful information to the reader, or are they merely decorative? Icons that differentiate among several parties (for example, icons used to indicate commander allegiance in Battle of the Atlantic) are likely to be useful, while icons that convey irrelevant or redundant information are usually not.
 * Can flag icons be used consistently? In other words, do all the groups in a given list have usable flags?  If only a few have them, it may be better to omit flags for all the items than to have a different layout for each one.
 * Will adding icons disrupt the existing structure or flow of the text? It is important to keep in mind that infobox templates permit limited useful width, so the use of flag icons in them can potentially conflict with readability.

When flag icons are used, they should be historically accurate ones. In particular:
 * When dealing with items related to a particular time period, avoid using anachronistic flags from other time periods. Be especially careful to avoid using the flags of modern countries for ancient ones; in many cases, the proper successor of a country no longer in existence is a matter of considerable controversy.
 * Avoid using national flags in inappropriate contexts, such as for groups or individuals not aligned with any country.

When dealing with biographical infobox templates, the most common practice is to use flag icons to indicate allegiance or branch of service, but not place of birth or death. However, there remains considerable disagreement regarding the appropriateness of flags in such cases, so editors should not regard this as a universal rule.

Precision
In general, articles should strive to be precise. Where the names of specific operations, formations, or commanders are available, for example, it is usually better to use them instead of more general terms; "The Ninth United States Army would launch an offensive, codenamed Operation Grenade, across the Roer" is likely to be more helpful to the reader than "The United States would launch an offensive across the Roer".

It is important to note, however, that the level of precision in an article should be appropriate for its scope. Articles dealing with narrower and more specialized topics can use more specific terminology than may be feasible in articles dealing with broad overviews or very general topics; and general terminology is often appropriate in an introductory section even where more specific terms are used in the body of the article. Precision should not be pursued to such an extent that it impairs the average reader's understanding of the topic.

Pronouns
Ships may be referred to either using feminine pronouns ("she", "her") or neuter pronouns ("it", "its"). Either usage is acceptable, but each article should be internally consistent and employ one or the other exclusively. As with all optional styles, articles should not be changed from one style to another unless there is a substantial reason to do so.

Try to avoid close, successive uses of the same referent for a ship by carefully using a number of referents in rotation; for example, "it/she", "the ship", and the ship's name.

Section length
Overly lengthy continuous blocks of text should be avoided; sections which are so long as to impede reader understanding should be broken down into subsections. There remains some disagreement regarding the precise point at which a section becomes too long, so editors are encouraged to use their own judgment on the matter.

Restricted sources
Articles that report on "black projects" and other classified topics are required to fully conform to Wikipedia's policies governing verifiability, original research, and fringe theories. All information presented in such articles must be appropriately cited to reliable sources as outlined above. The inadequacy of public sources may not be used to justify the inclusion of unsourced or poorly sourced material in an article or to relax normal standards of sourcing and citation.

Citation styles
In general, articles should use footnotes. A number of different formatting styles are available; so long as an article is internally consistent, the choice of which to use is left to the discretion of the major editors. Discursive notes are usually separated from reference citations (as here and here), but the two types are sometimes combined (as here). A single footnote may be used to provide citations for any amount of material; while they typically apply to one or a few sentences, they may also cover entire paragraphs or sections of text. In cases where the connection between the citations and the material cited is not obvious, it is helpful to describe it explicitly (for example, "For the details of the operation, see Smith, First Book, 143–188, and Jones, Another Book, chapters 2–7; for the international reaction, see Thomas, Yet Another Book, 122–191").

Requesting citations
Editors should take a reasonable approach when requesting citations. Unless the accuracy of a statement is in significant doubt, it is generally better to start with a request for citations on the article's talk page, rather than by inserting fact tags—particularly large numbers of such tags—into the article. Over-tagging should be avoided; if a large portion of the article is uncited, adding an unreferenced or citation style tag to an entire section is usually more helpful than simply placing fact tags on every sentence. Note that some articles contain per-paragraph citations, so checking the citations at the end of a paragraph may yield information about facts or figures in the paragraph as a whole.

Templates
The various primary and auxiliary infobox templates and navigation templates maintained by the Military history WikiProject are all coded to use a common set of styling characteristics. This is needed primarily because a number of the templates are designed to be stacked together to present the appearance of a continuous block; it is also beneficial for providing a consistent appearance to the entire set of articles within our scope.

Infobox templates
A few general guidelines apply to all military history infoboxes:
 * 1) Most of the fields in each infobox can be omitted if desired; the choice of which ones are appropriate for a particular article is left to the discretion of the article's editors.
 * 2) Multiple values given in a single field should be separated by both commas and, where appropriate, line breaks; merely spacing them onto separate lines can confuse screen reader software, and is ambiguous when long terms wrap onto multiple lines in their own right.
 * 3) Any use of flag icons should follow the relevant guidelines.

Primary infoboxes
A primary infobox is intended to provide a summary table for some topic. It should generally be placed at the top of an article, before the lead section; this will cause it to be displayed in the top right corner. Documentation may give advice on the appropriate way to populate parameters and should be followed.


 * infobox firearm cartridge : Used for cartridges and artillery shells.
 * infobox military award : Used for awards, decorations, and medals.
 * infobox military conflict : Used for all conflicts and combat operations, such as battles, campaigns, and wars. The "result" parameter has often been a source of contention. Particular attention should be given to the advice therein. The infobox does not have the scope to reflect nuances, and should be restricted to "X victory" or "Inconclusive". Where the result does not accurately fit with these restrictions use "See aftermath" (or similar) to direct the reader to a section where the result is discussed. In particular, terms like "Pyrrhic victory" or "decisive victory" are inappropriate for outcomes. It may also be appropriate to omit the "result".
 * infobox military memorial : Used for cemeteries, monuments, and memorials.
 * infobox military person : Used for personnel.
 * infobox military installation : Used for structures and facilities, including fortifications and bases.
 * infobox military test site : Used for test sites.
 * infobox military unit : Used for units and formations.
 * infobox national military : Used for an overview of a country's armed forces and expenditures.
 * infobox war faction : Used for factions participating in a war.
 * infobox weapon : Used for all weapons, including firearms, explosives, and armored vehicles.

Several infobox templates that are not specifically designed for military topics are also commonly used on military-related articles:


 * infobox aircraft begin : Used for aircraft.
 * infobox ship begin : Used for naval vessels.

Auxiliary infoboxes
An auxiliary infobox is a supplementary template intended to be used in conjunction with one of the primary infoboxes; it is usually placed directly below the primary infobox, but other layouts are possile. It is common for multiple auxiliary infoboxes to be used on a single article.


 * Infobox command structure : Used to indicate a unit's parent and subordinate units at a particular date.
 * Infobox operational plan : Used to summarize information about the planning and execution of a particular operation.
 * Infobox service record : Used to summarize a unit's or ship's service record.

Campaignboxes
A "campaignbox" is a type of navigation template that contains links to articles about the battles in a particular campaign, front, theater or war. See the template documentation for details.

Stub templates
There are a number of stub classes available for military history articles. The generic military history stubs are mil-stub and mil-hist-stub. For military people, see Category:Military personnel stubs. For a complete list of stubs, see the list of military history stubs and the list of military and weaponry stubs.

Overview
The category scheme originates in two root categories—Category:War and Category:Military—and can be thought of as two tree structures that intersect at several points. A guide to the top-level sub-categories of these two root categories is presented below; for brevity, a number of categories that are rarely used or lie outside the scope of this project have been omitted.


 * Category:War : Root category for matters related to wars and warfare (military or otherwise).
 * Category:Aftermath of war : Root category for all topics related to the effects of war.
 * Category:Anti-war movement : Root category for anti-war movements and resistance to war; see the Anti-war WikiProject for more information.
 * Category:Causes of war : Root category for all topics related to the causes and precursors of war.
 * Category:Law of war : Root category for topics related to the laws of war, including war crimes.
 * Category:Military and war museums : Root category for museums dealing with any aspect of warfare or military affairs.
 * Category:Military operations : Root category for specific military operations, such as wars and battles; see the section on conflicts and operations below for more information.
 * Category:People associated with war : Root category for people (both military and non-military) with some connection to warfare; see the section on people below for more information.
 * Category:Warfare by type : Classifies warfare by type (primarily by geographic or technological factors).


 * Category:Military : Root category for military matters (wartime or otherwise).
 * Category:Military by country : Classifies militaries by the organizing country.
 * Category:Military art : Root category for all types of artwork depicting the military.
 * Category:Military awards and decorations : Root category for all topics related to military awards and decorations.
 * Category:Military diplomacy : Root category for military-related aspects of diplomacy, such as alliances and treaties.
 * Category:Military equipment : Root category for military equipment, including weapons and vehicles.
 * Category:Military history : Root category for various classification schemes for topics in military history, as well as general historiographic topics.
 * Category:Military images : Root category for images related to the military.
 * Category:Military law : Root category for topics related to legal matters involving the military.
 * Category:Military life : Root category for topics related to life in the military.
 * Category:Military lists : Root category for military-related lists.
 * Category:Military locations : Root category for military locations, including structures and facilities.
 * Category:Military operations : Root category for all combat and non-combat military operations; see the section on conflicts and operations below for more information.
 * Category:Military organization : Root category for military organization, including units and other groups.
 * Category:Military personnel : Root category for military personnel; see the section on military personnel below for more information.
 * Category:Military-related organizations : Root category for organizations related to the military.
 * Category:Military science : Root category for topics related to military science, theory, and doctrine; see the military science task force for more information.
 * Category:Military terminology : Root category for specific military terms.
 * Category:Military veterans' affairs : Root category for articles related to the general topic of military veterans and veterans' organizations.

Most specific categories
In general, articles and categories should be placed in the most specific applicable categories, and should not be placed directly in a "parent" category if they are already present in one of its sub-categories. In other words, if an article is placed in Category:Wars involving the United States, there is no need to place it in Category:Military history of the United States as well.

Note, however, that this applies only to direct placement into a "parent" category; it is normal for a category to have multiple indirect paths up to some other category higher in the tree. For example, Category:Naval battles of the Spanish-American War is both a sub-category of Category:Battles of the Spanish-American War (which is a sub-category of Category:Battles involving Spain) and a sub-category of Category:Naval battles involving Spain (which is also a sub-category Category:Battles involving Spain); thus, there are two distinct paths from Category:Naval battles of the Spanish-American War up to Category:Battles involving Spain. This is especially common when dealing with intersection categories.

Nested categories
One important aspect of the "most specific" principle is that if every article in a category belongs to another category, it is sufficient to nest the categories directly, rather than double-categorizing each individual article. For example, Battle of Bosworth Field does not need to be added to Category:Battles involving England directly because Category:Battles of the Wars of the Roses is already a sub-category of it. Similarly, the articles in Category:Military units and formations of the United States Marine Corps do not need to be added to Category:Military units and formations of the United States directly.

In some cases, entire category trees will nest as above. For example, all "by war" categories should be sub-categories of the applicable "by period" category, and that a redundant "by period" label should not be applied to articles where a "by war" one is given (for example, Category:Military units and formations of the Crusades should be a sub-category of Category:Military units and formations of the Middle Ages, so an article already in the first need not be added to the second).

Note that this strategy should be applied only when every article in one category belongs in the other. For example, it is inappropriate to make Category:Battles of the Napoleonic Wars a sub-category of Category:Battles involving the United Kingdom, because there are many battles in the first category in which the United Kingdom was not a participant; thus, Battle of Waterloo must include both categories separately.

Intersection categories
In many cases, articles can be categorized through several parallel classification schemes, associating them with the related countries, wars, periods, and other topics. There are two general ways of applying multiple categories from these classification schemes to a particular article. The simplest, which can be sufficient for unusual combinations or small categories, is to apply each category separately. For example, a medieval French unit could be placed in both Category:Military units and formations of the Middle Ages and Category:Military units and formations of France. However, this system is unwieldy as category sizes increase; thus, common combinations of multiple categories can be made explicit by creating an "intersection" sub-category for them; for example, Category:Military units and formations of France in the Middle Ages.

The intersection category can potentially combine an arbitrary number of elements from the overall category structure, but categories that combine two or three are more common. For example, Category:Regiments of France in the Napoleonic Wars (units by size, by country, and by war), Category:Airborne units and formations of the United States Army in World War II (units by type, by branch, and by war), and Category:Naval battles of the American Civil War (battles by type and by war) are all potential intersection categories. It is recommended that intermediate "holder" categories (such as Category:Military units and formations of France by size or Category:Regiments by country) be liberally created in order to keep the overall category system navigable.

Note that the simpler system can still be used in conjunction with intersection categories to avoid the proliferation of extremely small and narrow sub-categories. For example, it may be better to place an article in both Category:Cavalry units and formations and Category:Military units and formations of France in the Middle Ages than to create an additional Category:Cavalry units and formations of France in the Middle Ages. A similar approach should be taken if there is no reasonable way to name a potential intersection category; for example, rather than creating the grammatically atrocious Category:Prisoner-of-war pilot generals of World War II, it is better to leave separate categories (Category:Pilots of World War II, Category:Generals of World War II, and so forth).

Conflicts and operations
The category tree for all conflicts and operations derives from the top-level Category:Military operations, as follows:


 * Category:Military operations
 * Category:Military operations by country : Organizes both combat and non-combat operations by the country (or non-state entity) that planned or executed them.
 * Category:Military operations by scale : Organizes operations by their operational scale.
 * Category:Battles : Root category for all battles; see the section on battles below for more information.
 * Category:Military campaigns : Root category for all campaigns; see the section on campaigns below for more information.
 * Category:Wars : Root category for all wars; see the section on wars below for more information.
 * Category:Military operations by type : Organizes both combat and non-combat operations by the "type" of warfare involved.
 * Category:Military operations by war : Organizes both combat and non-combat operations by the war during which they were planned or executed.
 * Category:Non-combat military operations : Root category for all non-combat operations.
 * Category:Cancelled military operations : Root category for both combat and non-combat operations that were planned but never executed.
 * Category:Lists of military operations : Root category for all lists of operations.

A particular country will thus have a tree of categories containing every operation in which it participated. At its greatest extent, the tree will take a form similar to this:


 * Category:Military history of the United States (also a sub-category of Category:Military history by country)
 * Category:Military operations involving the United States (also a sub-category of Category:Military operations by country)
 * Category:Wars involving the United States (also a sub-category of Category:Wars by country)
 * Category:Military campaigns involving the United States (also a sub-category of Category:Military campaigns by country)
 * Category:Battles involving the United States (also a sub-category of Category:Battles by country)
 * Category:Non-combat military operations involving the United States (also a sub-category of Category:Non-combat military operations by country)
 * Category:Cancelled military operations involving the United States (also a sub-category of Category:Cancelled military operations by country)

Note that, particularly for countries whose military history does not include the modern period, many of these categories may be omitted. In particular, it is common for the "Battles involving Foo" and "Wars involving Foo" categories to be placed in the corresponding "Military history of Foo" category directly, without a separate "Military operations involving Foo" category between them.

For historical states, categories below the "Military history of ..." level should be kept distinct from those of their successor states. For example, Category:Wars involving England is a sub-category of Category:Military history of the United Kingdom, but not of Category:Wars involving the United Kingdom.

A large war will have a similar tree of categories for every component operation; at its greatest extent, the tree will take the following form:


 * Category:American Civil War (categorized as discussed in the section on wars)
 * Category:Military operations of the American Civil War (also a sub-category of Category:Military operations by war)
 * Category:Campaigns of the American Civil War (also a sub-category of Category:Campaigns by war)
 * Category:Battles of the American Civil War (also a sub-category of Category:Battles by war)

The full tree is unnecessary for the vast majority of wars; the most common configuration is to have a simple two-level scheme:


 * Category:Wars of the Roses
 * Category:Battles of the Wars of the Roses (also a sub-category of Category:Battles by war)

Classifying conflicts
Specific conflicts are typically classified as battles, campaigns, or wars for the purposes of categorization. In this context, the terms are generally understood to mean the following:
 * A war is a conflict bounded by periods (however brief) during which the combatants are formally at peace with one another; it generally consists of multiple distinct component operations such as battles or campaigns.
 * A campaign is a coherent series of smaller operations with a defined overall goal; this goal may, however, change over the course of the campaign.
 * A battle is a single, distinct engagement generally limited to a narrow geographic scope and typically characterized by the opposing forces encountering one another, engaging in some form of combat, and then separating.

In general, articles should be classified according to what the topic actually is, regardless of the name used. For example, a series of engagements generally regarded by historians as a campaign should be categorized as one even if it's referred to as the "Battle of X".

Some operations and conflicts may need to be classified into more than one of the above levels; however, this should generally be done only when it substantially adds to a reader's understanding of the events. The possible double-classification scenarios are outlined below:
 * War and campaign: This can occur when a "sub-war" is fought as part of a larger war (for example, the French and Indian War, as part of the Seven Years' War). A subsidiary conflict is typically a "sub-war" when it includes some participants not involved in the larger conflict; the article can then be categorized as a war involving those participants, but as a campaign involving the participants of the larger conflict.
 * Campaign and battle: This can occur in modern warfare, where a long-term engagement has been treated by historians as either a single battle or a sequence of separate battles.
 * War and battle: This should generally be avoided, except in the few cases where a war consisted of a single large battle and only a single article covers the conflict.

Wars
Articles about wars are usually placed in three sets of categories nested under Category:Wars:


 * By date: a war article should always be placed in a category by century (such as Category:16th-century conflicts) for longer wars or by year (such as Category:Conflicts in 1878) for shorter ones.
 * By participants: a war article should generally be placed in one or more sub-categories of Category:Wars by country corresponding to the parties involved in the war. For example, a war between France and Austria should be placed in both Category:Wars involving France and Category:Wars involving Austria.
 * By continent: as an extension of the "by participants" categorization, war articles are placed under a sub-category of Category:Wars by continent. In virtually all cases, however, this categorization is applied directly to the by-participants category, rather than to individual articles; for example, Category:Wars involving France is a sub-category of Category:Wars involving the states and peoples of Europe.
 * By type: a war article may optionally be placed in one or more sub-categories of Category:Wars by type, such as Category:Civil wars or Category:Guerrilla wars.

Some larger wars have dedicated categories (such as Category:Hundred Years' War). In this case, it is sufficient to categorize the war category as above; the war article (Hundred Years' War, in this example) need only be placed in the associated war category.

Campaigns
Articles about campaigns are usually placed in three sets of categories nested under Category:Military campaigns:


 * By date: a campaign article should always be placed in a category by year (such as Category:Conflicts in 1878) corresponding to the period during which it took place. Longer campaigns spanning several years may be placed in multiple year categories, or in the corresponding decade or century categories in extreme cases.
 * By war: a campaign article may optionally be placed in a sub-category of Category:Campaigns by war; this should generally be done only for wars that have a substantial number of campaign articles.
 * By participants: a campaign article should generally be placed in one or more sub-categories of Category:Military campaigns by country corresponding to the parties involved in the campaign.

Battles
Articles about battles are usually placed in four sets of categories nested under Category:Battles:


 * By date: a battle article should always be placed in a category by year (such as Category:Conflicts in 1878) corresponding to the date on which the battle was fought. Longer battles spanning several years may be placed in multiple year categories, or in the corresponding decade or century categories in extreme cases.
 * By period: battles can be placed in one of the sub-categories of Category:Battles by period to indicate which of the broad periods of military history they belong to. For example, battles involving the Roman Empire would be placed under Category:Battles of antiquity.
 * By war: as an extension of the "by period" categorization, a battle article may optionally be placed in a sub-category of Category:Battles by war. For instance, the Battle of Agincourt is placed in Category:Battles of the Hundred Years' War.
 * By participants: a battle article should generally be placed in one or more sub-categories of Category:Battles by country corresponding to the parties involved in the battle. For example, a battle between France and Austria should be placed in both Category:Battles involving France and Category:Battles involving Austria.  Note that these categories are often moved out onto a "by war" category; see the section on categorizing entire sub-categories, above, for more details.
 * By type: a battle article may optionally be placed in one or more sub-categories of Category:Battles by type, such as Category:Sieges or Category:Naval battles. These are often combined with relevant "by country" or "by war" categories to create intersection sub-categories.


 * "Battles in ..."

One frequently asked question about this category scheme is why battles are categorized by participants, rather than by location; why are there no "Battles in ..." categories, in other words? The answer is that, unlike categorizing by participants, which is relatively intuitive and extremely useful, categorizing by location produces a scheme that is unintuitive and difficult to work with, at best, and completely meaningless and impossible to maintain, at worst.

There are two basic options when categorizing battles by location: using the modern countries, or using the historical countries that existed at the time of the battle. The first option—using modern countries—results in a category scheme that makes meaningless connections based on changes in geography centuries after the events discussed in the articles in question. The Siege of Königsberg in 1262, for example, would be classified as a siege in Russia, despite Russia not being involved in any way at the time. Similarly, the campaigns of individuals such as Alexander the Great would be scattered among dozens of countries in a fairly arbitrary manner. This is, at best, a less intuitive approach than categorizing by participants.

Categorizing by the historical location is even more problematic. The chief difficulty is that, unlike the participants in a battle (which are almost always uncontroversial), the ownership of the land where a battle was fought is often a matter of significant historical controversy—having, at times, been the cause of the battle itself! In cases where the territory was historically a disputed one, arbitrarily assigning it to one of the countries involved is highly problematic, due to our policy on maintaining a neutral point of view. Even in cases where ownership can be determined, however, doing so is quite often neither obvious nor intuitive, and requires an unreasonably detailed knowledge of the various diplomatic events of the surrounding period; this is particularly problematic in medieval and early modern Europe, where cities and territories regularly changed hands. For example, the various sieges of Milan in the early 16th century took place—fairly unpredictably—within the territory of either the Duchy of Milan, France, or Spain, depending on which country had been the last to receive the city in one of the myriad treaties during the period. Unlike categorizing by historical participants, which can be done from almost any description of the battle itself, categorizing by historical location thus requires an exhaustive knowledge of obscure diplomatic concerns, and is at times simply impossible due to underlying territorial disputes.

Units and formations
Articles about units and formations are typically placed into five sets of categories nested under Category:Military units and formations:


 * By country: units can be placed in a sub-category of Category:Military units and formations by country to indicate the state (or non-state entity, where appropriate) which they served. For example, units of the French military are placed in Category:Military units and formations of France or its sub-categories.
 * By branch: as an extension of the "by country" scheme, units of countries that had distinct branches or services in their militaries (such as an Army, a Navy, and an Air Force) can be placed in a sub-category of Category:Military units and formations by branch. For example, units that are part of the United States Navy are placed under Category:Military units and formations of the United States Navy, which is itself a sub-category of Category:Naval units and formations.
 * By period: units can be placed in one or more sub-categories of Category:Military units and formations by period to indicate which of the broad periods of military history they belong to. For example, Roman legions would be placed under Category:Military units and formations of antiquity.
 * By war: as an extension of the "by period" scheme, units associated with particular wars can be placed in one or more sub-categories of Category:Military units and formations by war; for example, units that fought in World War II are placed under Category:Military units and formations of World War II. This type of categorization is intended only for very major conflicts; creating a category tree for every recorded war is obviously unproductive.
 * By date: units can be placed in a sub-category of Category:Military units and formations by year of establishment, such as Category:Military units and formations established in 1917, corresponding to the year in which they were first formed.
 * By size: units can be placed in a sub-category of Category:Military units and formations by size, such as Category:Regiments or Category:Corps, as appropriate.
 * By type: units with a special role (such as airborne, artillery, or armored units), structure (such as mercenary or irregular units), or composition (such as expatriate or all-female units) can be placed under the appropriate sub-category of Category:Military units and formations by type; for example, a cavalry unit would be placed under Category:Cavalry units and formations.

A particular article need not be categorized with all of the possible category types; for some topics, certain of the category options are inapplicable or inconvenient labels.

People
The category tree for all topics related to people involved in warfare derives from the top-level Category:People associated with war:


 * Category:People associated with war
 * Category:People by war : Classifies all people (military and non-military) by the war with which they are associated.
 * Category:Children in war : Root category for topics related to children's involvement in warfare.
 * Category:Civilians in war : Root category for topics related to civilian involvement in warfare.
 * Category:Military personnel : Root category for soldiers and other military personnel.
 * Category:Women in war : Root category for topics related to women's involvement in warfare.

A large war will have a tree of categories for all people involved in it in some way; the tree will typically take the following form: undefined
 * Category:People of World War I (a sub-category of Category:People by war)
 * Category:Military personnel of World War I (also a sub-category of Category:Military personnel by war)
 * Various intersection categories for military personnel involved in World War I.

Equipment
For guidance about categorization of articles about military vehicles see Categorization of military vehicles. Military aircraft are categorized as per other aircraft – see WikiProject Aircraft/Categories.