From the Glossary in `/usr/share/doc/man-db/man-db-manual.txt` (source is manual/glossary.me):
> cat page
> A formatted manual page suitable for viewing on a vt100-type terminal.
>
> stray cat page
> A cat page that does not have a relative manual page on the system, i.e. only the cat page was supplied or the manual page was removed after the cat page had been created.