Commons:Template documentation

Templates are a very powerful feature of MediaWiki, but can be confusing to new users, and even experienced users can have difficulty making sense of the more complex ones. Templates should therefore be accompanied by documentation to improve usability.

Template documentation should explain what a template does and how to use it. It should be simple enough that a user without complete knowledge of the intricacies of template syntax – which includes many experienced contributors who focus their attention elsewhere – can use it correctly. This is especially true in the case of very widely-used templates.

What to include edit

Documentation should cover:

The basic purpose of the template: what it does, and (if it is not immediately obvious) why it needs to be done. If there are other templates with similar names or purposes, it's a good idea to mention those, to reduce the chance of the wrong one being used.
Any parameters that the template takes. Explain whether they are numbered or named, whether they are optional (and if so, what the default value is), and what effect they have. If a parameter can take only a limited set of values ("yes" or "no", for example), must be a number, or is constrained in some other way, this should be made clear.
Usage examples. Specify the exact wikitext that should be used, and the result it produces. The wikitext can be enclosed in <code>...</code> tags to make it clear and easy to copy, like this. If the template can be used in several different ways (with or without optional parameters, for example), provide a range of examples. A good way to do so is to transclude the template itself into the documentation a few times, with different parameters each time, and list the parameters used in each case.
Related templates. If the template is one of a series of templates, include links to these – in particular, ensure that every template in the series is linked from each of the others, as this makes navigation easier. (A separate navigation template may be useful for this purpose).
Appropriate categories and interwiki links, where applicable. Like the documentation, these must be contained within <noinclude>...</noinclude> tags.

Template documentation is often placed in a subpage of the template itself, which is then transcluded at the end of the template page. This separates the often complex template code from the documentation, making the documentation easier to edit. It also allows templates to be protected where necessary, while allowing anyone to edit the documentation. This method is sometimes referred to as the "template doc page pattern". However, short documentation can be placed on the same page.

Documentation of any sort on a template page itself should always be enclosed by <noinclude>...</noinclude> tags, so that it does not show up when the template is used on another page. Text on the template page itself adds to the amount of text which must be processed when displaying the template, which is limited for performance reasons. Placing the documentation in a subpage avoids this (MediaWiki developers have recommended it for this reason).

Manual edit

How to create a documentation subpage edit

Documentation subpages should be named and formatted using the following general pattern, for consistency.

Suppose your template is named Template:X. Create a subpage with the name Template:X/doc. Use the following wikitext as a start for the documentation:

{{documentation subpage}}
<!-- EDIT TEMPLATE DOCUMENTATION BELOW THIS LINE -->

<includeonly>
<!-- ADD CATEGORIES BELOW THIS LINE -->

</includeonly>

The top line will display the template {{documentation subpage}} at the top of the documentation; this makes it clear to the reader that what follows is documentation.

Insert the documentation and categories as below the appropriate comment lines – leaving the comments in place so that the layout is preserved when the page is edited in future. Ensure that the categories added are similar to [[Category:Name]], otherwise they will not work.

Save the subpage, and return to the template itself, Template:X in this example. Edit the template and append the following at the end of the template code:

<noinclude>
{{documentation}}
<!-- Add categories and interwikis to the /doc subpage, not here! -->
</noinclude>

This transcludes the documentation subpage into the template page.

Important: Make sure the opening <noinclude> begins on the same line as the last character of the template code (or text), and not on a new line. Otherwise, extra space will be inserted below the template when it is used, which is usually not wanted.

If the template is already protected, ask an administrator to do this, or request an edit by using {{editprotected}} on the template's talk page. If documentation, categories and interwiki links already exist in a section enclosed with <noinclude> and </noinclude> tags, move them into the documentation subpage, as it is best not to have documentation split across two separate pages.

Documentation on the same page edit

However it is better in most cases to create documentation on a subpage and include it with the template {{documentation}}, short documentation can be written on the same page, with templates {{doc-inline}} and {{doc-end}}.

To do it, put on the same line where the template code (or text) ends <noinclude>{{doc-inline}} and write the documentation text after that line. After the documentation put {{doc-end}} and categories, and </noinclude> at the end.

Examples edit

See the heavily-used Template:Cite web for an example of detailed template documentation. Note that the template itself is protected, but the documentation subpage, Template:Cite web/doc is unprotected and can still be edited.

See the much less used Template:MultiLink for an example of short documentation.

Note about interwiki links edit

Possibly, you have seen the recommendation to write interwiki links under categories. That recommendation is outdated. For now, interwiki links are placed at Wikidata.