This Global System for Mobile communications Technical Specification ( GTS) gives the stage 2 description of the call barring services. The possibility for a mobile subscriber to have certain categories of calls barred originated from or terminated at his access: Barring of outgoing calls (clause 1): - Barring of all outgoing calls (BAOC) (Barring program 1); - Barring of outgoing international calls (BOIC) (Barring program 2); - Barring of outgoing international calls EXCEPT those directed to the home PLMN country (BOIC-exHC) (Barring program 3). Barring of incoming calls (clause 2): - Barring of all incoming calls (BAIC) (Barring program 1); - Barring of incoming calls when roaming outside the home PLMN country (BIC-Roam) (Barring program 2). NOTE: The call barring program incoming calls when roaming outside th e home PLMN country (clause 2) is only relevant if as a general rule the called mobile subscriber pays the charges for the forwarded part o f the call from his home PLMN country to any other country.