Stationery Wiki has the Semantic MediaWiki extension installed.
You can find an introduction and explanation at the Semantic MediaWiki project pages.
If you want to try this out use the Semantic Wiki sandbox.
Example properties used
To indicate the manufacturer of the pen we use Made by, e.g. The Perkeo is an upcoming fountain pen from [[Made by::Kaweco]].
If the pen is actually manufactured by another company we could use Manufactured by instead.
For podcasts we currently the properties shown in the example below
podcast episode number=256
|podcast guest=Joey Cofone
|podcast length=75 minutes
To set a boolean data type use the following on the property's page
Valid Boolean options are: 1, 0, true, false, t, f, yes, no, y, n
More information can be found at Help:Property_declaration.