Not bad pemby, let me do some additional comments:
I: put out of service automatically by cyclic tests or MAO
X: put out of service manually by outserv command
T: terminal is unplugged, defective Terminal, miscall for analog stations
B: out of service due to a system bascul (normal on standby CPU until a bascul (switch to main role))
Y : out of service due to INTB loss / isolated crystal
N: Means out of service reason unknown
A: att_mserv, C: hs_defich, I: hs_isolauto, X: hs_isolman, T:hs_terdef
U: hs_usdef, P: hs_errparite, B: hs_bascul, Y: hs_cristisol, N: hs_inex