one of the documented procedures in this installation of the ACS
ad_style_footer   { string "" }   { tagset "" }
What it does:
Proc generated by ad_register_styletag to support the footer ADP tag.
Defined in: /web/philip/tcl/ad-style.tcl

Source code:

    global sidegraphic_displayed_p
    set signatory $string
    if [empty_string_p $signatory] {
	set signatory [ad_system_owner]
    if { [info exists sidegraphic_displayed_p] && $sidegraphic_displayed_p } {
	# we put in a BR CLEAR=RIGHT so that the signature will clear any side graphic
	# from the ad-sidegraphic.tcl package
	set extra_br "<br clear=right>"
    } else {
	set extra_br ""
    return "
<a href=\"mailto:$signatory\"><address>$signatory</address></a>