Template:Category union for files/doc

Description
This is a DPL (Dynamic Page List) template that finds the union of two categories, specifically for use in the File namespace. It is useful for creating combined lists of images that belong together or are linked in some way. The output is alphabetical by file name and is formatted like a category page. Redirect pages are included in the results.

Usage
There are two arguments,  and , that are passed through the URL so that this template may be used in multiple places. In the URL, the first argument after the page name must be delineated with a question mark,, otherwise the whole argument string is interpreted as part of the name and the wiki complains the page does not exist. The second argument and any others are delineated by an ampersand. The Magic Word  can be used to create the URL and will insert the question mark before the query_string for you. Note that spaces in the query_string must be replaced by underscore characters.

For example, a link that gives a list of Category:Maps of Luruar combined with Category:Maps of the Silver Marches would be constructed with: [ Example link 1]

Other examples: [ Gallery of maps for the Forest or the Spires of Mir] and a [ gallery of dogs and cats].