Callsign used by a military commander or leader in radio chatter to indicate the acting commander is speaking instead of that platoons Radio Telephone Operator (RTO).
If command calls the platoon and requests "Hunter Two-One", they'll be hailing the unit Hunter Two-One, and will therefore speak to the RTO. If command calls for "Hunter Two-One Actual" they are requesting the acting commander of that unit, as opposed to the unit as a whole (and the RTO).
-"Hunter Two-One Actual. Come in, Hunter Two-One Actual."
-"This is Hunter Two-One."
-"No, not the RTO. Hunter Two-One ACTUAL. Just put the lieutenant on the line."
A Forward Operating Base. Any secured forward military position that is used to support tactical operations. A FOB may or may not contain an airfield, hospital, or other facilities. The base may be used for an extended period of time. FOBs are traditionally supported by main operating bases that are required to provide backup support to them. A FOB also reduces reaction time and increases time on task to forces operating from it.