The comm parameter gives a supplementary comfort for designing a Template using a visual HTML editor (such as Dreamweaver or FrontPage). It enables you to enlarge the bounds of a locator to the bounds of the HTML comment (or any Xml/Html tag) which surround it.
With parameter "comm"
It is now 10:23:28
Without parameter "comm"
It is now 10:23:28
The merge result is identical with or without the 'comm' parameter. You can notice that the locator with parameter comm is visible only on the HTML source of the template.