Authors may add any metadata to a document and use these in their queries. The metadata may be displayed or hidden. This way authors can use metadata target at the reader and metadata used for authoring purpose.
The metadata for a document is specified by the use of the Document Properties Marker Macro. Each piece of metadata is called a document property, consisting of a name, a value, and document property controls.
The metadata can be used by query macros like the Display Table Macro or the Transclude Documents Macro to select on projectdoc Documents.
Properties can also be transcluded by the use of the for instance by the Display Document Property Macro and Display Document Properties Macro.