Comments

Comments End Tag: Required Support Key: Comment: 2 \| 3 \| 3.2 \| 4 \| IE1 \| M1 \| N \| O <!-- -->: 2 \| 3 \| 3.2 \| 4 \| IE1 \| M1 \| N1 \| O2.1	What is it? Attributes Tag Example	Parent/Content Model Tips & Tricks Browser Peculiarities
= Index DOT Html by Brian Wilson [bloo@blooberry.com] =

What is it?: Comments are regions of text and/or HTML tags that are ignored by the browser. Any text between the opening and closing comment delimeters will not appear on the screen. There are currently two methods to do this; the COMMENT element (obsolete) and the !-- -- delimiters (recommended.) The second method is a special HTML syntax originating from SGML and uses '' as an end delimiter. White space is allowed between the closing '--' and '>' but not between the opening '<!' and '--'. Comments are non-nestable.

Example: <!-- This is a comment -->
- OR -
<comment> This is a comment </comment>

Tips & Tricks

DTD Note: The <COMMENT> construct was considered an OBSOLETE element in HTML 2.0 and has disappeared from subsequent HTML proposals and standards.
The  syntax is almost universally supported, so it is highly recommended to use it instead of the COMMENT element in any situation.
You can comment out regions of HTML tags using the  syntax.
Note: This is the exact quote from the HTML 2.0 specification which describes the precise syntax of an SGML comment.
"To include comments in an HTML document, use a comment declaration. A comment declaration consists of `<!' followed by zero or more comments followed by `>'. Each comment starts with `--' and includes all text up to and including the next occurrence of `--'. In a comment declaration, white space is allowed after each comment, but not before the first comment. The entire comment declaration is ignored."
The strict view on this definition appears to allow multiple comment structures (such as ) to be legal. Also, under this interpretation, scripting expressions containing decrement operators (which is allowed in JavaScript) could prematurely end the parsing of a comment structure (with possibly undesired results.) Not all browsers interpret SGML comments the same, or this strictly, so keep this in mind when testing your documents.

Browser Peculiarities

Some early browser versions considered the end of a comment to occur with a > instead of the complete --> which created problems when nesting HTML tags in comments.