Help:Special properties

This page describes the special properties that are built-in to Semantic MediaWiki (SMW). They are needed to make the system work. They appear in a page's factbox, on Special:Browse and on Special:Properties in italic. Since SMW 1.4.0, special properties can be used in browsing interfaces and inline queries just like all other properties. Also see the help page Properties and types for more information.

The names and aliases of special properties are reserved and cannot be used for other properties. Additionally special properties should only be used according to their documented purpose! It is not necessary to create pages for special properties. They will perform their special behaviour even if your wiki does not have a property page for it.

The pages listed in the table below provide an overview and link to documentation pages for special properties.

You can create your own special properties in an extension using the  hook. See, for example, the usage in the Semantic Extra Special Properties extension, which provides extra special properties.

In case you would like to make special properties easier to be identified in the factbox, on Special:Properties and Special:Browse just add, e.g.

to the MediaWiki:Common.css page. Note that they are already printed in italics prior to the extra formatting mentioned here.