Template:Category pair/doc

This is a documentation subpage for Template:Category pair. It may contain usage information, categories and other content that is not part of the original template page.

This template is used on approximately 3,000 pages and changes may be widely noticed. Test changes in the template's /sandbox or /testcases subpages, or in your own user subpage. Consider discussing changes on the talk page before implementing them.

This template uses Lua: Module:Check for unknown parameters (sandbox)

Typical usage should be on dissimilar preceding/succeeding categories, or where a large gap exists in otherwise sequential categories. For similarly named sequential categories with gaps less than 5 years, use {{Navseasoncats}} instead.

• For 2 adjacent categories, a preceding Category:NAME1, and a succeeding Category:NAME2, place:

{{Category pair|NAME1|NAME2}}

at the top of the category page. Each category is displayed only if it exists. If neither category exists, nothing will be displayed.

• If there is no succeeding category, you may simply place:

{{Category pair|NAME1}}

an the top of the category page.

• If there is no preceding category, then leave the first parameter empty, and simply place:

{{Category pair||NAME2}}

an the top of the category page.

Preceding and succeeding categories, both exist

• {{Category pair|1934 FIFA World Cup|1950 FIFA World Cup}} →
  See also the preceding Category:1934 FIFA World Cup and the succeeding Category:1950 FIFA World Cup

Preceding category only, which exists

• {{Category pair|1934 FIFA World Cup}} →
  See also the preceding Category:1934 FIFA World Cup

Succeding category only, which exists

• {{Category pair||1950 FIFA World Cup}} →
  See also the succeeding Category:1950 FIFA World Cup

Preceding and succeeding categories, only preceding exists

• {{Category pair|1934 British Empire Games|1942 British Empire Games}} →

Preceding and succeeding categories, only succeeding exists

• {{Category pair|1946 British Empire Games|1954 British Empire and Commonwealth Games}} →

Two non-existent categories, so no output

• {{Category pair|AD 10 FIFA World Cup|AD 18 FIFA World Cup}} →

Only the first two parameters are processed, others are ignored.

If more than two parameters are supplied, a warning message is shown when the page is previewed. When it is saved, the page is added to the hidden tracking category: Category:Pages using category pair with more than 2 parameters.

If more than two parameters are supplied, the template is unlikely to do what the editor intended. For Category:NAME1, Category:NAME2, and Category:NAME3, for example:

• {{Category pair|NAME1|NAME2|NAME3}} will ignore Category:NAME3, and
• {{Category pair|NAME1|NAME2}} will ignore Category:NAME2, because a duplicate | character between the two categories causes Category:NAME2 to be the third parameter rather the second.

• Category:Pages using category pair with no output (9)

If neither parameter is a category which currently exists the template will produce no output. This is not necessarily an error; the other categories may simply be part of an incomplete series which will be completed in due course

• Category:Pages using category pair with more than 2 parameters (0)

See above: Error checking

• {{Navseasoncats}} — for similarly named sequential categories
• {{Preceding category}}
• {{Succeeding category}}
• {{Category see also}}
• {{Category see also if exists}}