cvs-prefix-setcvs-prefix-set is a compiled Lisp function in `
pcvs-util.el'. (cvs-prefix-set SYM ARG) Set the cvs-prefix contained in SYM. If ARG is between 0 and 9, it selects the corresponding default. If ARG is negative (or C-u which corresponds to negative 0), it queries the user and sets the -ARGth default. If ARG is greater than 9 (or C-u C-u), the (ARG mod 10)'th prefix is made persistent. If ARG is nil toggle the PREFIX's value between its 0th default and nil and reset the persistence.