This specification has been written for two groups of people; documentation authors and CHM capability implementors. We hope this specification will provide documentation authors all the resources they need to get the most out of its features and exploit the valuable undocumented features of HTML Help, whilst allowing them to skip over implementation details. Those who wish to implement alternative CHM compilers, decompilers and or viewers should find enough information to create such software.

This specification begins with a general introduction to HTML Help and proceeds to more specific technical information.

This specification has been designed for both screen and print media, with formatting and content tailored to the capabilities of the medium. For example in print media the location of external links are put in brackets after the text and internal links have chapter.section.subsection numbers instead. In electronic media various styles are used to convey contextual information.

All versions come with a tables of contents, a glossary and an index for quick access to information.