DEAL.SLIP.FORMAT

Which Temenos product are you using, T24 or Core Banking ???

The routine for Deal Slip has to be defined in FORMAT of DEAL.SLIP.FORMAT :

A User written Subroutine can be called to do the Formatting for this field. This Subroutine can be defined in this field with the name preceded by the '@' character. The Subroutine should have ONE argument which will contain the value of the Data or Text to be printed and can be changed by the User written Subroutine. Any errors can be flagged by setting the common variable ETEXT. This Subroutine must be defined on the PGM.FILE with a PGM.TYPE of 'S' i.e. Subroutine

EXAMPLE (returning formatted Date / Time no matter what is passed to it):
SUBROUTINE DSF.DATE.TIME(V.DATE)
$INSERT I_COMMON
$INSERT I_EQUATE
SYS.TIME = TIMEDATE()[1,5]
SYS.DATE = TIMEDATE()[10,LEN(TIMEDATE())]
COMI = SYS.DATE
CALL IN2D('','')
SYS.DATE = COMI
SYS.DATE = OCONV(ICONV(SYS.DATE,"D"),"D2.E")
V.DATE = SYS.DATE : '/' : SYS.TIME
RETURN
END

Beside I can't see any reason to have a DealSlip printed from FT the two mentioned fields can be used in DEAL.SLIP.FORMAT.
When they are empty on your printout maybe you should use another D.SLIP.FUNCTION (A instead of I ?).