This read-write value sets the caller category the Outgoing MFC register reports using the Mexican GroupII3 category list (normal-subscriber, atme-equipment, maintenance-equipment, operator-with-transfer-capability, or operator-with-intercept-capability). An admin configures this in addition to the general caller category object because Mexican signaling variants use their own distinct set of category codes that the Incoming register may request. For example, an admin provisioning a line used by an intercept operator would set this to operator-with-intercept-capability (5) instead of the default normal-subscriber (1).