2.2.5 Standard Properties

 Properties in the indexing service are represented by the combination of a property set GUID and either a string property name or an integer property ID. See CFullPropSpec for more details.

There are three classes of properties: database properties, query properties, and open properties. Database properties help control the indexing service behavior and are as specified in section 2.2.1.15.1. Query properties can be used in a restriction and in some cases returned with every result. They are special because they are built into the indexing service. Open properties are defined by individual applications. There are a typical set of common properties in use, but there is no requirement to use them.