Intercept of calls by the attendant terminal is controlled in accordance with ITR groups:

The allocation of the ITR group to the attendant group intercept is entered in a table by the VFGR AMO. An automatic process ensures that each of the groups 0-15 (though not all may have been entered) is assigned one ATNDGR. This is effected automatically by entering this ATNDGR in all ITR groups of the table when the first ATNDGR is set up with the VFGR AMO

Further ATNDGR can now be set up specifying precisely from which ITR group calls should be intercepted by this ATNDGR. The original entries will then be overwritten.