enum MtasSrvccOriginatingPreAlertingDT

0-1 (0=ORIG_PREALERT_SRVCC_DISABLED, 1=ORIG_PREALERT_SRVCC_ENABLED)

References from:
MtasSrvcc;

0
ORIG_PREALERT_SRVCC_DISABLED
SR-VCC for originating pre-alerting call is disabled
1
ORIG_PREALERT_SRVCC_ENABLED
SR-VCC for originating pre-alerting call is enabled
  enum MtasSrvccOriginatingPreAlertingDT