Hi! I'm about to throw away a shelf meter or so of SCO system V official documentation.
The original beige binders. I'm not sure if there is a shortage of these old books, but if anyone near Gothenburg, Sweden has use for them. Drop me a line at : martin (dot) rudolfson at mac (dot) com
Documentation for Xenix and Unix up to to 3.2.4 was published in three ring binders.
Some versions of 3.2.4 were also published in olive/yellow covered paperback.
Documentation for Openserver 5.0.0 through 5.0.6 is published in white paperback books.
Documentation for Openserver 5.0.7 and 6.0.0 is available at The SCO Group, Inc. | Support | Docs | Documentation
Three!
It's more like 8.
Xenix 2.2 I believe. With names such as Graphics interface guide, Text processing guide, C programming guide etc. But there might actually be three headlined User Guide.
With the presence of the internet my guess these are more of curiosities.