I block it at my sites by using the NCOS on the sets.
I set up an RLI in load 86 just for 1411 so it is easy to make changes. Set it up like this:
>ld 86
ESN000
REQ NEW
CUST 0
FEAT RLB
RLI xx
ENTR 0
LTER
ROUT y
TOD
CNV
EXP
FRL z
DMI 0
press enter for the rest of the prompts.
xx is the new RLI number
y is the outgoing route
z is the FRL. This corresponds to the NCOS on the sets. If the NCOS is lower than this FRL, the call will not go through.
You must then find and change the entry for 1411 in LD 90:
>ld 90
ESN000
REQ PRT
CUST 0
FEAT NET
TRAN AC1
TYPE SPN (IT WILL EITHER BE SPN OR NPA USUALLY)
SPN (or NPA) 1411
SPN 1411
FLEN 0
RLI 1
SDRR NONE
ITEI NONE
Change this RLI above to your new RLI you just built.
The only downside is you will now need to make sure anyone who you want to have access to 1411 has an NCOS equal or higher than the FRL you set up, and anyone you don't want to have access has a lower NCOS. Needless to say, this could be a real pain. You may want to do some research as to how your NCOS is set up now on your sets. This is something I set up on my new installs whether they want to restrict it or not, that way I don't have to try and set it up later.
Sorry this is so long, but this can be confusing. If anyone has an easier way, tell me. I can admit when I'm off base.