Should I include an NSFW warning if my link is not safe for work? What about spoilers?
Generally if what is behind a link is not safe for work (porn, nudity, shock sites, sound) a NSFW indicator is appreciated. Admins will sometimes add NSFW to links, especially front page posts, if the poster doesn't include them. The same is true for spoilers -- posts that indicate the ending of a book, movie, sporting event etc -- please try to be polite and include them inside the thread or a [more inside] section rather than in the post itself. Mods do not police spoilers on the site except to try to keep them off the front pages of the subsites.
Do not assume that all content that isn't safe for work browsing will be labeled as such. There are always instances where the NSFW indicator is missing, and the admins cannot be expected to catch every single one of them and fix it. The same is true for spoilers, which the admins will try to tuck inside a post but otherwise do not alter or edit. When browsing, it is safest to consider the NSFW tag and the spoiler indication a favor performed by the admins and posters, rather than an expectation or obligation. ROT-13, while a great way to avoid spoilers, is problematic for a large diverse community and should probably be avoided when possible.