AT&T MERLIN LEGEND System Reference Manual page 98

Features
Specify the FRL and/or digits that must be added when people dial
emergency numbers in the special number or N11 table.
Tables-> ARS -> More -> SpeclNumber -> ARS FRL or ARS
D i g i t
Specify the pool routing, FRL, and digits or special characters that must be
added by the system to the number dialed by the user when calls are routed
on the dial 0 table.
Tables -> ARS -> More -> Dial D -> ARS Pool or ARS FRL or
ARS Digits
Automatic Route Selection 2-49