one of the documented procedures in this installation of the ACS
ad_custom_list   db   user_id   item_group   item_set   item_type   target_url   custom_url   { new_string "new view" }
What it does:
Generates the html fragment for choosing, editing and creating user customized data
Defined in: /web/philip/packages/acs-core/table-display-procs.tcl

Source code:

    util_dbq {item_group item_type}
    set items [database_to_tcl_list $db "select item from user_custom 
    where user_id = $user_id and item_type = $DBQitem_type
    and item_group = $DBQitem_group"]

    set break {}
    foreach item $items { 
        if {[string compare $item_set $item] == 0} {
            append html "$break<strong>$item</strong>&nbsp;(<a href=\"$custom_url$item\">edit</a>)"
        } else { 
            append html "$break<a href=\"$target_url$item\">$item</a>"
        set break " | "
    append html "$break (<a href=\"${custom_url}CreateNewCustom\">$new_string</a>)\n"
    return $html