A command is a special marker used to access TopLeaf functions that are not available through the standard mapping dialogs. A command within custom content looks and behaves exactly like a tag in an XML document. Commands and custom markers form an XML-like hierarchy so that the content forms an XML fragment. Details of this structure are given in “Custom content structure”.

Although commands can have content between the start and end tags, in most cases this content is not used by the command. The exceptions are the ones shown with start and end tags in the list below, and those that document how the content is processed (such as the <set> command).

The end tag of a command that ignores its content does not terminate the range of the command. This is a potential source of confusion and should be avoided. For example:

<font-properties color="red">WARNING</font-properties>

does not reset the font color after “WARNING” — the color is applied to the whole content of the element being mapped.