BDSM and rape
do you have a link to some common tags? yes, i can google, but asking is so much more social!

Common tags? Well, there's not so much a 'list' of standards. They come in a few categories:
Subgenre tags: People will mark a subgenre of some fics, indicating what people can expect from them. For example, a fic that's categorized as a hurt/comfort fic might be sub-genred 'wumph' (more hurt than comfort) or 'fluff' (more fuzzy feelings and comfort than hurt). Romance fics are further categorized this way, as het (heterosexual romance), slash (homosexual romance, but canon gay couples are almost never referred to as 'slash') or any number of things. Fics that are what-ifs, altered setting, or other elseworlds are labeled 'au' for Alternate Universe. Fics that are close to the canon material without romantic pairings outside of what was originally there are often called 'gen' or 'genfic.'
Content warning tags: These help people avoid fics that may have content they don't want to read and are often one-word warnings inserted after the summary text, such as 'rape,' 'torture,' 'depression,' 'suicide,' 'angst,' etc. Sometimes suffixed with fic, such as 'rapefic.' These warnings are also provided for sexual content, such as 'lemon,' (a graphic sex scene within) or 'lime,' (a homosexual graphic sex scene within, less prevalent)... and in fetish circles can be used to identify specific fetishes.
Pairing tags: In fandoms that have more than one possible romantic pairing, people will proclaim which ones are featured in the material so people can find their preferred set. Usually they are either separated by slashes (Link/Zelda) or smushed together to make one term (ZeLink). Pairings are serious business in fandom so not marking them can make people mad.
Other Fic Elements: Some people mark whether their story has original characters (OCs) or not, too... and other details. For example, if writing a fic about the marvel universe, one would need to list what continuum it's set in.
So an example summary that might appear on fanfiction.net might look a bit like:
The Most Rational Fic, by RationalWikian
KnightOfTL;DR and Godot discuss fanfiction warnings. Genfic.
Most of the crap I read on the internet is marked up like M/f, F/m, F/f, MF/ff...
Anyway, new ambition in life: 1) Become famous and popular author. 2) Troll the fuck out of Fanfiction.net with bad fanfiction of my own stuff.
Nah, not ambitious enough. You should become a neuroscientist and try to top Survey Fail.