National - I think that FuzzieAlum is on target in that you don’t need NIC or anyone else’s blessing to be “national.” It depends on what your governing body decides. Now certain umbrella groups have different criteria for membership that does include a specific number of chapters. NPC, for example, states that a national organization must have at least 13 chapters. The last chapter established cannot be less then two years old. I am not sure about NIC though. You may also want to check out the Professional Fraternity Association.
www.profraternity.org/index.html
Incorporated – This is really related to the business aspect of the organization. All of the NPC, NIC and NPHC organizations are incorporated as well as many other GLOs. A group doesn’t have to be incorporated to exist but it saves A LOT of hassles if you are. However, the use of the term “incorporated” is a preference particular to each one. AOII is incorporated but it is our policy to use the term only when legally required. There have been numerous discussions on GC about this topic.
Good luck.