I declare the stored procedure like this:

CREATE PROCEDURE TEST0.TBTESTS2
(IN L_CLNT_ID CHAR(8),
L_BNK_NBR CHAR(4),
L_AGT_NBR CHAR(4),
L_CARD_TYP_CDE CHAR(1),
OUT X_PARMLST VARCHAR(502))

But when I display it looks like this:
X 0 ????? N 0
L_CLNT_ID P 1 CHAR N N 8
L_BNK_NBR P 2 CHAR N N 4
L_AGT_NBR P 3 CHAR N N 4
L_CARD_TYP_CDE P 4 CHAR N N 1
X_PARMLST O 5 VARCHAR N N 502

What do you mean with "display"?