Most members of S.N.A.I.L. where trained by the FBI or by some other part of the government before they joined. A good portion of them where mutants that had lived their lives with the secret until S.N.A.I.L. found them. With the advancement of the ability to track the mutant gene, it has become important that troops are trained from the start, and by S.N.A.I.L. With the ever present threat of alien attack secret special forces had to be created.

Note: When looking at each S.N.A.I.L. O.C.C. there will be a section that states the best type of squad the O.C.C. would fit best. They are listed from most likely to least likely. Below is a list of what each of the symbols means, and what the type of squad is.

The different types of S.N.A.I.L. squads are:

Alpha: Main combat squad, used to destroy and/or eliminate an area, or target. Used for pure destruction.

Beta:Used for information gathering, and retrieval. Second to destroy. They are the most used, because they have the greatest range of skills and experience.

Gamma:They are defense. They are brought in after an area has been cleared, or they need to protect an area from attack.

Phi: This squad is a special division of Gamma. They are a total medical and clean-up crew. They are the units sent in to take back any physical or other "samples" gathered by other teams. They are also the PR group that contains any unauthorized persons, that may have seen or been a part of Alien or supernatural activities.

Omega:They are the major undercover operatives. They are sent into deep cover missions, often infiltrating gangs, criminal organizations, and other large military bodies that might be a problem for S.N.A.I.L.

Delta:These are the complete robotic, or cybernetic squads. Often an off-shoot of the Alpha squad, they are the forces that have been rebuilt, or constructed by S.N.A.I.L.

Psi: This is the psionic squads. Every member has some kind of psionic powers. This group is used to track down, and gather other psionics, or very powerful, and potential new agents.

Pi: This is the magic squads. Every member has some kind of magic powers. They are mostly researchers, or investigators. They are a minor squad which is used to watch and observe.

Each squad is designated with the greek letter that depicts their class, and then two sets of numbers. The first set of numbers is the designation number or order in which the squad was created. The second set of numbers is the number of times the squad has been retro-fitted or rebuilt. A squad is retro-fitted when more then two thirds of the original members have been killed or transferred to a new squad. A squads designation number is almost never retired, but it has been known to happen for some of the earlier squad numbers.