cvs-dired-use-hook is a variable defined in `pcvs.el'.
Its value is

  • This variable may be risky if used as a file-local variable.

Whether or not opening a CVS directory should run PCL-CVS.
A value of nil means never do it.
`always' means to always do it unless a prefix argument is given to the
command that prompted the opening of the directory.
Anything else means to do it only if the prefix arg is equal to this value.

You can customize this variable.