one of the documented procedures in this installation of the ACS
What it does:
If a help file isn't available for the currently executing .tcl script, return empty string. Otherwise, returns a hyperlinked anchor of "help" that will take a user to /help/for-one-page.tcl
Defined in: /web/philip/tcl/help-defs.tcl

Source code:

    # we may have multi-lingual help but right now we don't care; let's
    # just look for anything that starts with the URL filename and ends with .help
    set pageroot [ns_info pageroot]
    set helproot [ad_parameter HelpPageRoot help ""]
    set helproot_fullpath "$pageroot$helproot"

    # full path name will always start with the page root, so we want to cut off the page root from 
    # head of the full_path_name string in order to get a full_url
    set full_path_name [info script]
    set full_url [string range $full_path_name [string length $pageroot] [expr [string length $full_path_name] - 1]]

    set just_the_dir [file dirname $full_url]
    set just_the_filename [file rootname [file tail $full_url]]
    set help_file_directory "$helproot_fullpath$just_the_dir"
    set glob_pattern "${help_file_directory}/${just_the_filename}*.help"
    set available_help_files [glob -nocomplain $glob_pattern]

    if { [llength $available_help_files] == 0 } {
	return ""
    } else {
	# if page is served through /groups directories then help link should be /groups/group/help.tcl
	# otherwise help link should be /help/for-one-page.tcl
	if { [uplevel \#1 {info exists scope}] && [uplevel \#1 {expr [string compare $scope group]==0}] && [uplevel \#1 {info exists group_vars_set}] } {
	    # page is served through /groups pages
	    upvar \#1 group_vars_set group_vars_set
	    set group_public_url [ns_set get $group_vars_set group_public_url]
	    set help_url "$group_public_url/help.tcl" 
	} else {
	    set help_url "/help/for-one-page.tcl"

	return "<a href=\"$help_url?url=[ns_urlencode $full_url]\">help</a>"