ITL also allows you to use '<!--[' and ']-->' as interchangeable alternatives to plain square brackets: [tagname] and <!--[tagname]--> are equivalent.
This allows you make your raw tags appear as comments to HTML browsers or editors. You might want to do this if your editor has trouble with ITL tags when editing Interchange page templates, or alternatively, if you want to use one .html file both as an Interchange template and as a static page delivered directly by your web server, without Interchange processing.
To properly HTML-comment contained body text, place your comment-style brackets appropriately, for example:
<!--[tagname] Contained Body Text [/tagname]-->
Note that you must include whitespace between the HTML comment delimiters and the square brackets if you wish to actually comment out tag output in the browser. For example, if [value name] expands to 'Bill':
'<!--[value name]-->' becomes 'Bill' '<!-- [value name] -->' becomes '<!-- Bill -->'
While '<!--[' and '[' are completely interchangeable, the Interchange parser does not replace ']-->' with ']' unless it also sees '<!--[' at least once somewhere on the page. (This is a small parsing speed optimization.)
See the Template Parsing Order appendix if you are modifying the special administrative interface pages and intend to use this syntax.