You can have hints for editing displayed in the preview by defining a
section using an npsgui element and placing HTML text into
this section. During the export, this section is ignored. Example:
<npsgui> This text is only visible in the editorial preview. </npsgui>
Using Comments
The npsgui element can also be used for including comments in
layouts. The comments are not displayed in the Content Navigator and are not
present in the published pages. Example:
<npsgui><!-- This layout calculates the secondary (left) navigation --></npsgui>