So the idea behind veteran is players simply get the rank if they meet the following conditions:
1) They are trusted
2) Have been trusted for a year or more.
There would be no way for a player to get this rank unless they meet the above two things. Especially the one year or more part (or whatever time requirement would be to put in place).
This rank would offer no bonus perks except for a different colored name, and because only trusted members can get veteran then the rank would basically be trusted but with a different color name. The point of it is to just show who's been on the server for a long time (time requirement), and also very/somewhat active (trusted people don't get the rank by not being active).
I haven't seen anything like this suggestion. There has been this rank suggested before but for ex-moderators, or for trusteds to be promoted to in order to get a couple extra perks. Well, no. This rank offers nothing but recognition that a player is an old-timer on this server and was or is active enough to be trusted.