As people have probably noticed, Dominaria's release notes were spoiled (there's already a discussion on that in the forums), and people are unsurprisingly excited. Heck, legendary sorceries are already added!
However, I ask that if a person is interested in using concepts from the Dominaria leaks in the forums, they note that there may be spoilers within their comment or discussion, as @TezzeretofCarmot21
did by saying "(spoiler alert)" in the title of the discussion of the spoilers.
I don't mean to be condescending or rude (I certainly hope I'm not coming off like that), but I know from experience that some people enjoy discovering a set by going to a prerelease or release event, and would rather not have seen the concepts of the cards or mechanics beforehand if possible. So please, if you are posting a comment or discussion on these forums that concerns the leaked release notes in some way, please leave some kind of indication that what you are doing may have spoilers for Dominaria, just in case people would rather not look at it.
(By the way, yes, I have looked at the spoilers, but that doesn't mean I don't care whether other people also have the choice.)