I tried doing a brief search on the subject and came up empty handed so please don’t destroy me if it has already been discussed.
I have been wondering for some time now about many aircraft tail numbers that have a U.S. registration but do not have the standard “N” number. Specifically those that begin with “TN” i.e. TN320FX, TN212RG, TN333PC, etc.
What is the point of this and does it signify anything special?