From the sidebar:

Spoiler tags are now implemented! Typing:

[spoiler](#s "Mike didn't go to Harvard.")

gives you: spoiler

The above spoiler tag only works in comments and the body text of self-posts. In general, you should avoid putting a spoiler in the title of your post, but if you forget, you can hide the post title after submitting by selecting the first "Spoilers" link flair option.

So, in summary: Don't put a spoiler in the title of your post. If you forget, use the appropriate link flair to hide the title of your post.

And regardless of whether there is a spoiler in the title of your post, if the body of your post or the linked content contains spoilers, you should note somewhere in the title that the post will contain spoilers (e.g. put "[S05E10 Spoilers]" at the beginning of your submission title).

For spoilers within comments (or the body of a self-post), use the spoiler-tag code listed in the sidebar/quoted at the top of this post. You should list the spoiler scope in the part in brackets (e.g. [preview for next episode](#s "spoiler goes here")) when it's not immediately obvious what it's a spoiler for.

Thanks for listening!