Template:Category see also if exists 2/doc

Displays a "see also" link to a category, if it exists. Otherwise, it will optionally display a "see also" link to a second category, if that exists. Similarly with the third and fourth parameters.

If none of the categories exists, it does nothing.

Note that category redirects are resolved.

Purpose
This template is a variant of Category see also if exists, with added provision for a fallback category if the first one does not exist.

It allows the creation of a link to a category which may not yet exist, but which will be displayed if and when the category is created. This is useful as a category tree is being developed, because the editor does not have guess whether the target category is likely to exist any time soon. The link can be created now, rather than having to edit the page again later.

This template can be used in other templates such as estcat, or directly on category pages or articles.

Usage

 * Usual syntax

Parameters:
 * 1) category name
 * 2) optional second (fallback) category name. If the first category does not exist, the second will be tested in the same way, and linked only if it exists.

→ →  →  →
 * Examples
 * 1) A category which does exist:
 * 1) A non-existent category:
 * 1) A non-existent category with a fallback category that does exist:
 * 1) A non-existent category with a fallback category that also does not exist:

The outcomes of the above examples 1, 3 and 4 are displayed at Category:1915 establishments in South West Africa, Category:1919 establishments in South West Africa and Category:1955 establishments in South West Africa.


 * Extended syntax

The optional third and fourth parameters are tested in turn to see if they exist if neither the first nor second parameters exist.

Redirects

 * Cat see also if exists 2