Board Thread:Support Requests - Getting Technical/@comment-4970747-20150929084252/@comment-1251315-20150929085409

If you mean adding things to the right rail, you can't do it anyway. The site-wide JS file (Common.js) on all wiki's is locked down and appears to be staying that way for the foreseeable future. At this time, the only possible method is through personal JS, which will only show to yourself.