Guillaume Paumier wrote:
It would be even better to modify one's monobook.js to add usual block messages. It's possible to add buttons with usual delete messages on Your_page&action=delete pages, so I think it's possible to add some buttons on [[Special:Blockip/Your_vandal]].
Thus, you could add buttons which enter usual messages in plain language, even with a wiki link to [[WP:3RR]] for example, just by clicking.
Firefox at least will helpfully offer to autocomplete your block messages based on what you've entered earlier. So you only need to type each block message once, and you can then reuse it as often as you like.
Also, a little-known and often misunderstood feature of block messages is that templates included in them are expanded when the message is shown to the blocked user (but not in the block log). I'm not sure how many templates designed for this already exist, since they don't seem to be categorized in any way, but at least {{blocked proxy}} has been used like this.