Man page quotation characters

I've just been looking through a few man pages for a few different commands including grep and ifconfig. I've noticed over a few pages, the content uses a strange syntax to notate what i think are quotations (back-tick followed by a single or double quote): `text' Why can't they use ' or " to open _and_ close quotations? **Update** I now realise that this should be bolding out the characters instead of noting quotes. Is there any reason my system is ignoring these when formatting? I'm using OSX.