These are character sequences that may appear in HTML documents; they represent sometimes useful symbols that are not part of the standard ASCII set or that would be difficult or impossible to type otherwise (e.g. the less-than sign, which would always be mistaken for the beginning of an HTML tag). Case is signinficant. The content of this table has been throughly tested. If the character that appears in the first column does not fit the description in the third column, your browser has a screw loose.