This is not strictly patent related, except that it highlights the importance of careful drafting. As illustrated by this cautionary tale, imprecise language can occasionally come back with a vengeance to bite you and/or your client.
The Globe and Mail reports on “the most costly piece of punctuation in Canada,” in which one ambiguously drafted clause costs Rogers Communications over $2M in a contract dispute. (Actually, the culprit is not exactly the punctuation per se, but rather a poorly drafted sentence.)