Input is written as XML according to one of the DTDs and output is corresponding HTML. Documentation for an Erlang/OTP application is usually organized as follows:

In some cases, one or more of the User's Guide, Reference Manual and Release Notes are omitted. Also, it is possible to use either the application or part DTD to write other types of documentation for the application.

The generated HTML corresponding to a part or application document is split into a left frame and a right frame. The left frame contains information about the document and links to the included files, that is chapters or manual pages. The right frame is used to display either the front page for the document, or the selected chapter/manual page.

The left frame also contains links to a bibliography and a glossary, which are automatically generated.

In the case of an application document, the left frame also contains a link to an automatically generated index.

All DTDs in the OTP DTD suite share a basic set of tags. An author can easily switch from one DTD to another and still use the same basic tags. It is furthermore easy to copy pieces of information from one document to another, even though they do not use the same DTD.

The basic set of tags are divided into two categories: block tags and inline tags. Block tags typically define a separate block of information, like a paragraph or a list. Inline tags are typically used within block tags, for example a highlighted word within a paragraph.

In this User's Guide, the structure of the different documents and the meaning of the tags are explained. There are numerous examples of documentation source code.

For readability and simplicity, the examples have been kept as short as possible. For an example of what the generated HTML will look like, it is recommended to look at the documentation of an OTP application.