Note that the opening and closing codes are not symmetrical. If you end it with <nowiki>--!></nowiki> by mistake, it won't really end, and everything else after that on the page will be hidden.
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Note that the opening and closing codes are not symmetrical. If a comment is eneded with <nowiki>--!></nowiki> by mistake, it won't really end, and everything else after that on the page will be hidden.