WARNING: BEFORE YOU READ THIS, THIS BUG WAS CREATED AFTER THE RELEASE OF 17W50A.
When I type in chat "/give" I can see some commands which are SUPPOSED to be in MP only, but for some reason are in SP.

Here is a list (in alphabetical order)

/ban
/ban-ip
/banlist
/deop
/kick
/list
/op
/pardon
/pardon-ip
/save-all
/save-off
/save-on
/setidletimeout
/stop
/whitelist

Mojang, if you are reading this, please fix this.