Determining if a file was included or requested directly:

Compare the value of the [Response_FilePath] and [Include_CurrentPath] methods. If they agree then the page is being loaded directly, otherwise the page is being loaded as an include or library file.

Code

if(Response_FilePath == Include_CurrentPath)
    'This page was loaded directly.'
else
    'This page was loaded as an include.'
/if

Result

This page was loaded as an include.