The kind of documentation no one reads, that is just here to please some manager, or meet some compliance requirement. These are, unfortunately, the most common kind I see, by volume. Usually, they are named something like QQF-FFT-44388-IssueD.doc and they are completely outdated with regard to the thing they document despite having seen several revisions, as evidenced by the inconsistent style.
Common features are:
- A glossary that describe terms that don't need describing, such as CPU or RAM, but not ambiguous and domain-specific terms, of which there are many
- References to documents you don't have access to
- UML diagrams, not matching the code of course
- Signatures by people who left the project long ago and are nowhere to be seen
- A bunch of screenshots, all with different UIs taken at different stages of development, would be of great value to archeologists
- Wildly inconsistent formatting, some people realize that Word has styles and can generate a table of contents, others don't, and few care
Of course, no one reads them, besides maybe a depressive QA manager.