Help XML Reference
This reference documents all the tags and attributes used in the Microsoft Help project files or XML data islands in HTML topic files. Each tag has one or more associated attributes, as defined in the Microsoft Help document type definition (DTD) files.
Some tags have one or more attributes in common; however, the attributes may not serve the same purpose, depending on the context.
All Microsoft Help project files are in XML format.
Microsoft Help accepts all standard Unicode character references for special characters. That is, you can reference arbitrary Unicode characters, even if they are not available directly on the keyboard. Character references are numeric and can be used without any special declaration. The basic format of a character reference is either &#nnn; or &#xhh; where nnn is a decimal Unicode character number and hh is a hexadecimal Unicode character number.