Some time ago I wrote document describing common problem with cleaning up=20
HTML. PHP manual states some little warning about topic but no solution on=
=20
http://www.php.net/strip_tags

Many websites are still vulnerable and similar problems happen not dependin=
g=20
on programming language too often:

http://www.jes.ee/~tonu/strip.php

Please do not start flamewar, I know some people might find this informatio=
n=20
useful. Yes, it is not "advanced" and this is why people often do not notic=
e=20
the problem.

T=F5nu