one of the documented procedures in this installation of the ACS
vc_fetch_root   { path "" }
What it does:
Fetches the CVSROOT associated with path If path is not specified, looks under acs_root_dir. This is always overridden by the CVSROOT parameter in the ini file.
Defined in: /web/philip/tcl/vc-defs.tcl

Source code:

    # Try the system default
    set root [ad_parameter CVSROOT vc]

    # If not defined we go to the fallback methods
    if [empty_string_p $root] {
	if { [empty_string_p $path] } {
	    set cvs_root "[acs_root_dir]/CVS/Root"
	} else {
	    set cvs_root "[file dirname $path]/CVS/Root"
	if {[file exists $root]} {
	    set root [gets [set fp [open $cvs_root r]]]
	    close $fp

    return $root