Using %TYPE in function defs

Answered my own question by TRYING it .... oooooo .... scary for a responsible 44 year old, who
knows the cost of experiments gone wrong. But OTOM, my instllation is just starting so I could
break something and not cry about it.

It is possible to define a function using %TYPE. Maybe this could be put in the manuals?
------------------------------------------------------------
CREATE OR REPLACE FUNCTION add_usr ( Usrs.first_name%TYPE,
Usrs.middle_name%TYPE,
Usrs.sur_name%TYPE,
Usrs.sur_name_extra%TYPE,
Gens.gen%TYPE,
EmailAddrs.email_addr%TYPE,
UsrEmailAddrTypes.usr_email_addr_type%TYPE,
UsrEmailAddrs.pri_for_usr%TYPE)
RETURNS BOOLEAN AS '
DECLARE
var_first_name ALIAS FOR $1;
var_middle_name ALIAS FOR $2;
var_sur_name ALIAS FOR $3;
var_sur_name_extra ALIAS FOR $4;
var_gen ALIAS FOR $5;
var_email_addr ALIAS FOR $6;
var_usr_email_addr_type ALIAS FOR $7;
BEGIN
RETURN ''f'';
END;
' LANGUAGE 'plpgsql';