They had both understood professional etiquette; nothing must come of any feelings, and thus better to leave them unfelt-or at least unsaid.

That I regard as a distinct breach of professional etiquette.

I also believe at the highest levels of motorsport there should be a professional etiquette.

This was a definite breach of professional etiquette and he didn't intend to stand for it.

I asked him, but he just gave me a lot of hot air about protocols and professional etiquette.

He said it was a matter of professional etiquette, of protocols.

It would have been a breach of professional etiquette.

He told her most of the Patrick story, a serious breach of professional etiquette.

At the same time, his relationship with his boss begins to cross the line of professional etiquette.

She considered asking about it directly, but decided it would be a breach of professional etiquette.