Per code review feedback on r45171. This seems to be easier than
reverting it wholesale, but anyone who would like to do that instead
should feel free.
/**
* Allow id's that don't conform to HTML4 backward compatibility requirements.
- * This is currently for testing; if all goes well, this option will be removed
- * and the functionality will be enabled universally.
+ * This is purely experimental, has multiple known flaws, and will likely be
+ * renamed and reconcepted based on HTML5 in the future, so should not be used
+ * except for testing.
*/
$wgEnforceHtmlIds = true;