Chances are it had to come in on official letterhead from some law office.

A sealed letter with official letterhead and stamps arrived for them.

This correspondence must be on official letterhead and signed by the Member.

This correspondence must be accompanied by a signed cover letter on official letterhead.

A sponsoring Member must submit a letter, on official letterhead, to the Committee with the following information:

It was alleged that Olmert sometimes used official letterheads.

Everybody is entitled to their own personal opinion, but when it's on official letterhead, I don't know what the message is.

The request must be submitted on official letterhead, and include the following information:

The emblem can also be used on documents issued by the government, including money, passports and official letterheads.

The funniest instance he remembered was when a report card that arrived from Mexico on an official letterhead was translated.