You can use the following syntax to include the contents of one topic inside another:

 {{NameOfTopicToInclude}}

This is basically as simple as it looks with one subtle addition. If you add some tabs before the include, the number of tabs you use will be used to show headings in included topics as deeper level than they would appear in the original topic. For example, two tabs before the include directive would cause a level 1 heading (i.e., preceeded by one !) as level 3. You can use this to make a WikiSpec.

For more information, examples and discussion, see IncludeFormattingRules.