N7 is a vocational code in the Systems Alliance military. The "N" designates special forces and the "7" refers to the highest level of proficiency. It applies to Alliance personnel who have graduated from the Interplanetary Combatives Training program.
The highest grade of training, N6, provides actual combat experience in conflict zones throughout the galaxy. From day one, invitees are given basic gear, then separated and stranded on an asteroid with no nav data. The test ends when the last person runs out of oxygen. The first few are out of the program. If the trainee survives these scenarios in "admirable and effective fashion," they finally receive the coveted N7 designation. N7 is the only ICT designation that may be worn on field or dress uniforms.