We (aka. the people who are insane and rewriting all the bloody FAQs) think that the title should be more generalized to reflect all the restrictions discussed in the FAQ, but also make mention of JavaScript and Flash so that people who've heard of those but don't have a lot of technical knowledge about them will still recognize it as being relevant.
Two possibilities so far:
Why are scripting languages (such as JavaScript and Flash) and some HTML tags forbidden on LiveJournal?
Why are JavaScript, Flash, and some other scripts and HTML tags forbidden on LiveJournal?
Please comment if you have alternative suggestions, or if you like one of these choices.