woman-manpath-man-regexp

woman-manpath-man-regexp is a variable defined in `woman.el'.
Its value is

"[Mm][Aa][Nn]"

Documentation:
Regexp to match man directories UNDER `woman-manpath' directories.
These normally have names of the form `man?'. Its default value is
"[Mm][Aa][Nn]", which is case-insensitive mainly for the benefit of
Microsoft platforms. Its purpose is to avoid `cat?', `.', `..', etc.

You can customize this variable.