From the book of unholy style guide wars: That versus Which
For anyone who spends time battling MS Word, the back issues of Editorium newsletter provide much to read.
In a newsletter about pet peeves, there's:
My pet peeve about Word's "help" is its default enforcement of the alleged rule against using "which" to introduce a restrictive (essential) clause in a sentence. I've appended a longish e-mail (below) that I sent to a local electronic discussion group a while back explaining why the rule doesn't hold water. But the short version is that it was originally simply a mild preference expressed by H. W. Fowler in his famous _Modern English Usage_ (1926). The preference got picked up by AP and was soon presented as grammatical gospel, reproducing itself via journalism teachers all over the United States, in spite of the fact that it fails to reflect most normal educated usage.
Seriously, does anyone really use Word's Grammar check? There's some more to that discussion and a link to a longer discussion at Electric Editors; small quote:
> QUESTION: In which Anglophone cultures is this distinction still
> being maintained and for what reason?
It is still maintained among some writers and editors here in the U.S. (especially those trained in journalism schools, it seems), but by no means above all. It's interesting to see how many people consider this distinction to be a "rule" of some kind. I like the distinction myself, and I use it, but I don't require that our copy editors impose it. When, as I do, a writer tends to automatically make the distinction, his or her writing will flow around it naturally. But when a writer has not made the
distinction him- or herself, the mechanical replacement of restrictive "which" with "that" often negatively affects the cadence of the sentence or the author's voice.