Board Thread:Support Requests - Community Management/@comment-8438345-20130420042537/@comment-1038387-20181116212744

If you are an admin on a wiki, you could lock it and still edit it, but if you are not, then a lock would also lock you out.

But preferably, you don't. Vandalism is easily reverted. Unless something is a high profile page or structure template, there's no real need to protect anything a priori.