User:Martin of Sheffield/sandbox/bookclass/doc

This template produces a Wikipedia hatnote directing the user to where libraries may shelve books on the subject.

Function
If readers wish to follow up on a subject it will help to start looking under the appropriate classification in a library. The template currently supports:
 * Dewey – Used in 200,000 libraries in at least 135 countries.
 * UDC (Universal Decimal Classification) – Used in around 150,000 libraries in 130 countries.
 * LCC (Library of Congress Classification) – Used by most research and academic libraries in the U.S. also used in several other countries.

Template Data
{ "description": "Help the reader to find books in a library on this subject", "params": { "dewey": { "label": "Dewey", "description": "Dewey class number", "suggested": true, "example": "dewey=621.3", "type": "string", "aliases": [ "1" ] },   "lcc": { "label": "LCC", "description": "LCC class number", "required": false, "example": "lcc=QC501–721", "type": "string" },   "udc": { "label": "UDC", "description": "UDC class number", "required": false, "example": "udc=663.12:57.06", "type": "string" }  } }