You do not have permission to edit this page, for the following reason:
The action you have requested is limited to users in the group: Users.
You can view and copy the source of this page.—MarcoAurelio (talk)
Return to Thread:Support/Edit request/reply.
I've asked around and this is because that message supports Raw HTML and, as such, it's also protected so only interface-administrators can edit it. MediaWiki and Meta-Wiki docs should be updated to reflect that this messages are also covered by the enhanced restrictions, as the MediaWiki messages covering that topic as well IMHO.
Edit: docs have been updated.