The conversation was strictly unofficial, being nominally about colonial matters and the subject of China.

According to Reventlo, there was no official cargo to be flown, which meant there was room for the strictly unofficial kind.

I would act as a strictly unofficial conduit.

"This mission is strictly unofficial," Kirk said.

First of all," said Tommy, "speaking in a strictly unofficial capacity, let me point out this.

Your assignment, if we can call it that, is strictly unofficial.

Gently setting down his own tea, Pardek replied, "This conversation is strictly unofficial."

Unless otherwise noted in the text, these fees are strictly unofficial.

Two men, working independently, came up with reports, strictly unofficial, but important.

"His presence in the war zone would have to be strictly unofficial."