Structured wiki help
Semantic wiki facilities
Semantic Mediawiki (SMW) add database-like features to the free form functionality of wikis. Annotations, properties, templates, forms and queries can be used to more consistently create content, suitable for re-use.
An annotation is a simple discrete markup of information, with a corresponding property, which describes the data type. Annotations can appear anywhere in text, except in values of other properties. They look like this: [[birthday::November 25, 2009]].
Once annotations are entered, they can be reused in queries and views, like this one:
{{ #ask: [[birthday::+]] | format=timeline}}
Which means ask for all pages with birthdays, and display them in timeline format, including links to page names (Structured wiki help in this case).
Other formats include graphs, maps, facet browsers, tables and charts. The property type is often a page, so the annotation provides a link type. This corresponds to RDF triples - object (the page), predicate (the link), subject (the destination link). SMW has RDF features to support interaction with other software.
Properties are commonly assigned in templates and used with forms to provide consistent data using fields and categories. Special:CreateClass provides functionality to create a template and form in one step.