The real power of properties comes in the ability to stick queries into pages. That is, pages don't have to be entirely static text: they can also have generated text, based on the properties on this page or others. There are two major types of queries. This page will cover Property Substitutions, and the next will cover Page Queries.
Property substitutions are queries that basically say, "insert the values of the specified properties in this text". They currently come in three major flavors: variable substitution, property lists and property checks.
Variable substitution is the simplest of all queries, and underlies all of them. It just says, "stick the value of a named property here". The syntax looks like this:
%%propname%%
So say that we have the following property definition:
ExamplePageAbstract = Describes the basic ways to put properties in pages.
Then this variable substitution:
%%ExamplePageAbstract?%%
would render like this:
Describes the basic ways to put properties in pages.