Comment 4 for bug 1275866

My fault. I forgot that the --allow option requires a fix I did on libxml2, which appears to not be in any released version yet. I'll ping the libxml2 maintainer about getting a release out.

The patch is still fine. You just can't do the bestest in Mallard validation without building libxml2 from git master. You can use --strict without any --allow options, but it'll complain about any pages where you're using ITS or experimental features. You can also use yelp-check validate without --strict. It just might not report errors in how you've used things like conditionals or UI expanders.