An alias directive could work like an inverse redirect, but in a more maintainable way. Currently, a page might have several redirects leading to it, without an easy way of enumerating them. Therefore, the following directive is suggested for addition (possibly by means of a plugin):

The alias and aliastext directives implicitly create redirect pages to the page they are used on. If two or more pages claim a non-existing page to be an alias, a disambiguation page will automatically generated. If an existing page is claimed as an alias, it will be prefixed with a note that its topic is also an alias for other pages.

All aliases to a page are automatically listed below the backlink and tag lists at the bottom of a page by default. This can be configured globally by setting the alias_list configuration option to false, or set explicitly per alias by specifying list=true or list=false.

Similar to the taglink directive, aliastext produces the alias name as well as registering it.

Usage example

Greece.mdwn:

Greece, also known as [[!aliastext  Hellas]] and officially the
[[!aliastext  "Hellenic Republic"]], is a …

<!-- there are so many people who misspell this, let's create a redirect -->
[[!alias  Grece list=false]] 

This page by itself will redirect from the "Hellas", "Hellenic Republic" and "Grece" pages as if they both contained just:

[[!meta  redir="Greece"]]

If, on the other hand, Hellas Planitia also claims [[!alias Hellas]], the Hellas page will look like this:

**Hellas** is an alias for the following pages:

* [[Greece]]
* [[Hellas Planitia]]

The proposed plugin/directive could be extended, eg. by also including old-style redirects in the alias list, but that might introduce unwanted coupling with the meta directive.

On second thought, implementing this might have similarities with auto-create tag pages according to a template -- the auto-created pages would, if the way of the alias directive is followed, not create physical files, though, but be created just when someone edits them.

If multiple plugins do such a trick, they would have to fight over who comes first. If, for example, we have a setup where not yet created tag pages are automatically generated as "[[!inline pages="link()" archive="yes"]]" and aliases are enabled, and a non-tag pages grabs a tag as an alias (as to redirect all taglinks of the tag to itself), there are two possibilities:

• The autotag plugin comes first:
  • autotag sees the missing tag and creates its "[[!inline" stuff
  • alias sees that there is already content and adds its prefix
• The alias plugin comes first (this is the prefered way):
  • alias sees the empty page, sees it is not contested by other alias directives and creates its "[[!meta" redirect
  • autotag sees there is already content and doesn't do anything

That issue could be handled with "priority number" on the hook, with plugins with a lower number being called first.