I see ranks and positions bandied about all the time on FT, and I must confess that I don't know what all of them mean or how they fit together. I'm curious about this stuff; because employees of this agency can make life rather difficult for me when I fly, I want to understand the structure as much as possible. Knowledge is power, and when entering a situation where you have limited power over your own person, any small tidbits can give you an advantage. So I have a whole litany of questions:

I know that TSO means Transportation Security Officer, which refers to the blue-uniformed people who work for TSA and conduct screenings. I know that their ranks are designated by stripes on their epaulets. What I don't know is... well, pretty much anything beyond that.

There are one-stripers, two-stripers, and three-stripers. There are LTSOs and STSOs. Which are which, and what do the L and S preceding the TSO mean?

I gather that certain TSOs are designated training officers. Do they have any additional rank or insignia on their uniforms? Are they all of a minimum rank (i.e. any training officer must be a minimum of a __-striper)?

Are there 4-stripers or 5-stripers?

Is there a specific title for the person who is in charge at a single checkpoint, like "checkpoint supervisor", or is the highest-striped TSO at a specific checkpoint simply in charge by default?

I also gather that the head of TSA operations at any given airport is the Federal Security Director, or FSD. Is the FSD a uniformed position? Is FSD a single position, like the manager of a hotel, or is it a multiple position, so that there is always an FSD on duty at any given time, 24/7? Is there any position between the front-line TSOs at the checkpoint and the FSD? Who is the next person in authority above the FSD?

Are there any other TSA ranks or positions that I'm likely to encounter when I go through the airport, either in or out of the checkpoint?