I am joing the marine corps reserves?

The first thing you need to do is to get an MOS igned. That will determine where your closest reserve base will be. Each reserve base has different units with different jobs, i.e. Philadelphia, PA has an artillery unit. What area you want to go to will help your recruiter narrow down your job choices. Secondly, about the addresses, the first line is the unit name. Co-Company, Bn-Battalion, and 23rd Marines is short for the 23d Marine Regiment. So what all that means is that is the address for India Company, 3d Battalion, 23d Regiment. Its an organizing system to distinguish between different jobs and locations. Anything with HMLA, MAG, or VMFT is all air units. 23d Marines is more likely an infantry regiment. Ask your recruiter for more details concerning all this. If he's not an idiot, he'll know answers to all this, if he is, find out who his boss is and talk to him. Hope some of this helps. Good luck on becoming a Marine. Its one of the most challenging and rewarding careers you can have.