WordPress is “helpfully” converting double-hyphens to – which is Unicode’s U+2013 “en dash”. This is nice, but messes up Gnu longopts, as in my post about top. This conversion even occurs inside <pre> blocks. No option for “stop messing up what I’ve typed” is apparent in the blog settings.
The only way that I’ve found around it is to use ampersand-hash-four-five-semicolon instead of either/both of the hyphens.
UPDATE 2008-08-11: Someone (from WordPress.com?) has chimed in in the comments and pointed to this. I’ve not tested it, it doesn’t deal specifically with shell options and I don’t really want highlighting anyway, but it’s a start. I’d still prefer a “don’t mess up what I’ve typed” option, which is what <pre> is already supposed to be…