Right, you're wrong ;-)
I only want a simple thing:
To comment out previously written HTML in a manner that the comment is *not* visible later in the finally generated HTML code.
So I want some kind of "<!--" and "-->" but *not* visible later.
So a template tester/creator has the option to comment out some stuff and - may be - reactivate the code in future ... but nobody out there needs to know internals about the template variables (which also would be visible within normal HTML comments).
I hope it get's more clear now :-)