Editing Module:Check for unknown parameters/doc (section)

== Usage ==
=== Basic usage ===
<pre>
{{#invoke:check for unknown parameters|check
|unknown=[[Category:Some tracking category]]
|arg1|arg2|arg3|argN}}
</pre>
or to sort the entries in the tracking category by parameter with a preview error message
<pre>
{{#invoke:check for unknown parameters|check
|unknown=[[Category:Some tracking category|_VALUE_]]
|preview=unknown parameter "_VALUE_"
|arg1|arg2|...|argN}}
</pre>
or for an explicit red error message
<pre>
{{#invoke:check for unknown parameters|check
|unknown=<span class="error">Sorry, I don't recognize _VALUE_</span>
|arg1|arg2|...|argN}}
</pre>
Here, <code>arg1</code>, <code>arg2</code>, ..., <code>argN</code>, are the known parameters. Unnamed (positional) parameters can be added too: <code><nowiki>|1|2|argname1|argname2|...</nowiki></code>. Any parameter which is used, but not on this list, will cause the module to return whatever is passed with the <code>unknown</code> parameter.  The <code>_VALUE_</code> keyword, if used, will be changed to the name of the parameter.  This is useful for either sorting the entries in a tracking category, or for provide more explicit information.

By default, the module makes no distinction between a defined-but-blank parameter and a non-blank parameter. That is, both unlisted {{para|foo|x}} and {{para|foo}} are reported. To only track non-blank parameters use {{para|ignoreblank|1}}.

By default, the module ignores blank positional parameters. That is, an unlisted {{para|2}} is ignored. To ''include'' blank positional parameters in the tracking use {{para|showblankpositional|1}}.

=== Lua patterns ===
This module supports [[:mw:Extension:Scribunto/Lua reference manual#Patterns|Lua patterns]] (similar to [[regular expression]]s), which are useful when there are many known parameters which use a systematic pattern.  For example, [[template:infobox3cols]] uses
<pre>
| regexp1 = header[%d][%d]*
| regexp2 = label[%d][%d]*
| regexp3 = data[%d][%d]*[abc]?
| regexp4 = class[%d][%d]*[abc]?
| regexp5 = rowclass[%d][%d]*
| regexp6 = rowstyle[%d][%d]*
| regexp7 = rowcellstyle[%d][%d]*
</pre>
to match all parameters of the form <code>headerNUM</code>, <code>labelNUM</code>, <code>dataNUM</code>, <code>dataNUMa</code>, <code>dataNUMb</code>, <code>dataNUMc</code>, ..., <code>rowcellstyleNUM</code>, where NUM is a string of digits.