Template:Cat handler/numbered/doc

Technical details
This sub-template makes it possible for its parent-template to take input in two forms:

This sub-template takes a bunch of numbered parameters. There's no limit to the number of parameters it can use, other than what the servers and MediaWiki system can handle.

It also takes a parameter named data. If data is a number, then it returns the data of the corresponding numbered parameter. If data is something else, for instance a category name, then it returns data unchanged.

Here's how you would normally call this sub-template:

In the above example, since the parent-template feeds only 1-4, then only the numbers 1-4 will work properly. Feeding other numbers will return an empty string.