Correct, you will never see it on official correspondence. It is used only used on informal correspondence such as memos, notes and e-mails.If you really want to get into the weeds, Google the Navy Correspondence Manual. Vr is never used for official correspondence. It's more of an informal closing, in fact it isn't even mentioned in the Manual. I think, but don't take this as gospel, it is mentioned in OPNAVINST 1710.XX, the Protocol manual.