An anchor element MUST contain something other than whitespace, or it won't work on many browsers. The image is a clickable imagemap. These three characters should be escaped with the above ampersand entities everywhere in a document where they are not intended to be used with their HTML meanings. The stuff in such a tag is ignored. Theoretically, a comment can include other HTML tags, but you're much wiser NOT doing this, since many implementations don't support it.
Some implementations restrict comments to a single line.
Where protocol is one of http , gopher , ftp , file , telnet , wais , news , mailto , etc. A fully absolute URL contains a protocol prefix, and a full hostname for external DNS resolution. Encloses the entire form. Some type of input field. A list of items to select.