Comment tags are like meta tags in that they can't be seen on your page but they can be read by servers/browsers. Comment tags for the most part are just that. They are used for leaving comments on your page, so when you view the html to edit it, you can find your place on the page faster. Such as|
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Comment tags can also tell servers/browsers to do or not to do certain things. The best example of this is using comment tags to keep children from viewing certain parts of or a whole web site, that is if parents have done their job and use the screens, filters or software available to them to prevent younger viewers from accessing sites with these tags. If your site has any material on it that may not be appropiate for younger viewers, be responsible and put one of the comment tags below on your page. Remember if you put the comment tag on you main/entrance page your whole site will not accessable to viewers with filters. You can just do certain pages on your site.
Comment tags can be used anywhere on a page, but for the browser/server to read this tag and act on it, it needs to be placed after the <html> tag and before the <head> tag. Any of these tags will be read by most browsers/servers.
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