+When run with the --sanitize switch, which is turned on by default (see
+[[usage]], ikiwiki sanitizes the html on pages it renders to avoid XSS
+attacks and the like.
+
+ikiwiki excludes all html tags and attributes except for those that are
+whitelisted using the same lists as used by Mark Pilgrim's Universal Feed
+Parser, documented at <http://feedparser.org/docs/html-sanitization.html>.
+Notably it strips `style`, `link`, and the `style` attribute.
+
+ikiwiki uses the HTML::Scrubber perl module to perform its html
+sanitisation, and this perl module also deals with various entity encoding
+tricks.
+
+While I beleive that this makes ikiwiki as resistant to malicious html
+content as anything else on the web, I cannot guarantee that it will
+actually protect every user of every browser from every browser security
+hole, badly designed feature, etc. I can provide NO WARRANTY, like it says
+in ikiwiki's [[GPL]] license.
+
+The web's security model is *fundamntally broken*; ikiwiki's HTML
+sanitisation is only a patch on the underlying gaping hole that is your web
+browser.
+
+----
+
+Some examples of embedded javascript that won't be let through.
+
+<span style="background: url(javascript:window.location='http://example.org/')">test</span>
+<span style="any: expression(window.location='http://example.org/')">test</span>
+<span style="any: expression(window.location='http://example.org/')">test</span>