Help:Special property Allows value list

The Allows value list property is a special property in Semantic MediaWiki with a built-in meaning: it assigns a reference which is used to define a page which allows to map a list of permissible values to the referencing property. It was introduced with .CiteRef::gh:smw:2295

The referenced page is located like a system message in the "MediaWiki" namespace and consists of the string "Smw_allows_list_" and the stored reference as a suffix to it, e.g. "MediaWiki:Smw_allows_list_..." with "..." being replaced by the reference added to this special property.CiteRef::sb:smw:2295

Starting with it is possible to add values lists in JSON format to improve handling of lengthy and challenging to edit via wikitext lists.CiteRef::gh:smw:3289 The value list is using a simple key, value assignment with the key (e.g. "CC BY 2.5") being used as constraint value with the assigned value argument is there only to described the key and has for the validation no specific relevance.CiteRef::sb:smw:3289

Usage
Two steps have to be taken to use this special property when choosing the wikiktext or json approach:

Wikitext

 * 1) Add   to a property page for defining a page reference, e.g.   will define page "MediaWiki:Smw_allows_list_licenses".
 * 2) Add permissible values as listed items starting either with "*" or "**" to the "MediaWiki:Smw_allows_list_..." page, e.g.

JSON

 * 1) Add   to a property page for defining a page reference, e.g.   will define page "MediaWiki:Smw_allows_list_licenses.json".
 * 2) Add permissible values as listed items in JSON-format to the "MediaWiki:Smw_allows_list_..." page, e.g.

Note

 * It is possible to assign as well as this special property to a property page at the same time.