Sec. 36.373  Services--Account 6620.

    (a) For apportionment purposes, the expenses in this account are 
first segregated on the basis of an analysis of job functions into the 
following classifications: Telephone operator services: publishing 
directory listing; and all other.
    (1) Expenses may be apportioned among the operations for groups of 
exchanges. A group of exchanges may include all exchanges in the study 
area.