If it is, could you please acknowledge this by signing and returning the attached copy of this letter.

Thus it is unusable for authentication by cryptographic signing.

We get along by signing - our own brand - but it suffices.

But the impressive showing was clouded somewhat by lower-than-expected signing of new contracts during the quarter, which were below $10 billion.

We ask you to acknowledge your understanding and acceptance of these by signing and returning the accompanying form.

That way, by signing, installation could commence immediately.

By signing, a viewer pledged "never-ending loyalty and allegiance to the best comedy on television today."

In this case you'll be asked to confirm the agreement in writing by signing and returning a formal letter.

Please confirm that the foregoing is in accordance with your understanding by signing and returning to us the enclosed copy of this letter.

You can help with that by signing.