Semantic MediaWiki (SMW)

 https://www.semantic-mediawiki.org/wiki/Semantic_MediaWiki
Every property has its own article in the wiki, just as every category has an article.

• You can see all the properties in use in the wiki with special page Special:Properties
• Just as category articles are prefixed with Category:, all property articles are prefixed with Property: to distinguish them from other articles.

Property "types" can be set using [[Has type:: as shown in this example:

https://wikidelphia.org/index.php?title=Property:Contact_Email&action=edit

• So you can also also use MediaWiki's special page "Search" to find existing properties.
• As with categories, a property's article can be empty, but it is strongly recommended to add a description that explains the intent of the property and its proper usage.

In-text annotations and property declarations are case-sensitive and therefore adhere certain MediaWiki configuration settings (e.g. configuration parameter $wgCapitalLinks) and if changed arbitrarily may cause content to be rendered invalid or unavailable during query execution.

Silent or Hidden in-text annotation uses an empty pipe |
i.e. a pipe character with a space after it thus:
[[Has population::2,229,621| ]]
[[Located in country::France| ]]

Info

• Introduction to Semantic MediaWiki
  • Help:Classification
  • Help:In-text Annotation
  • Help:Special:Properties
  • Help:Properties and types
  • Special:Properties
• User manual

Searching

• Semantic Search (Special:Ask)
  • Help for #Ask
• Query construction
• Search for a property: [[Contact Email::

Search for a property: [[p:

Search for a category: [[c:

[[Category:Musical actor]] OR [[Category:Theatre actor]] or more concisely,

[[Category:Musical actor||Theatre actor]]

::[[Category:Is-Business]] ::[[Contact Email::

• Special:SemanticMediaWiki