Recommendation Q.118

       -    The last paragragh of 4.3.2 is replaced by the following text:

       "During the establishment of a connection to a PABX extension it  is  not
appropriate to send a clear back signal. However, if a PABX returns a clear back 
condition, the duration must be less than 10  seconds,  so  that  it  would  not
unintentionally clear the connection, especially on calls from networks with short time-out.1"

       -    Add footnote:

"1  For call where the charging is applied to called  party  (e.g.,  free  phone
service) the time-out may be reduced. The value to  be  chosen  is  for  further
study."