Gary
SPN's are looked at after a 9 is pressed,if you go into LD 90 and print the spn's you can see them all, they are excellent for steering calls, barring etc, the reason you only need to enter 23 is that there is a SPN 1 already programmed so as soon as you dial 9 123 it refuses the call,the same if you want to bar 192 ,, DENY 92,,,,
Colin