What directives are available?

The valid SSI directives are as follows:

echo

Syntax: echo var=”environment-variable”

Echo inserts the value of one or more SSI environment variables.

include

Syntax: include file or virtual=”path”

The include directive inserts the text of another document, specified either as a file or a virtual file.
Path must be relative to the current document in the case of a file, or it can be a virtual path. For example: