one of the documented procedures in this installation of the ACS
ad_user_group_column_type_widget   { default "" }
What it does:
Returns an HTML form fragment containing all possible values of column_type
Defined in: /web/philip/packages/acs-core/user-groups-procs.tcl

Source code:

    return "<select name=\"column_type\">
<option value=\"boolean\" [ec_decode $default "boolean" "selected" ""]>Boolean (Yes or No)
<option value=\"integer\" [ec_decode $default "integer" "selected" ""]>Integer (Whole Number)
<option value=\"number\" [ec_decode $default "number" "selected" ""]>Number (e.g., 8.35)
<option value=\"date\" [ec_decode $default "date" "selected" ""]>Date
<option value=\"text_short\" [ec_decode $default "text_short" "selected" ""]>Short Text (up to 200 characters)
<option value=\"text\" [ec_decode $default "text" "selected" ""]>Long Text (up to 4000 characters)
<option value=\"special\" [ec_decode $default "boolean" "special" ""]>Special (no form element will be provided)
</select> (used for user interface)