|This page in a nutshell: Do not do that which creates rancor amongst good faith contributors. People are not obliged to memorize policies and guidelines before editing.|
Wikipedia has a lot of policies and guidelines. They have evolved from the early days, due to consensus. For instance, we have experimented with various standards of notability over the years, and years of experience have allowed us to judge that, in the absence of anything else, coverage in reliable sources is a good "one size fits all" method of doing so. More specific guidelines, such as those to do with biographies of living people, resulted from something that required the guideline to be made. A huge list of policies and guidelines have been created to solve various problems, and remembering every single one of them is impossible.
What this means is that policies and guidelines are not the law and do not need to be ruthlessly enforced. New users, in particular, haven't encountered all the discussions that led up to the notability and verifiability policies, so they won't necessarily know that adding unsourced content is a bad thing. It's really important not to come down like a ton of bricks on them—they don't deserve to be treated like they've just kidnapped the First Lady.
In fact, even users who've been around for a while might not have come across certain parts of Wikipedia where those policies are most relevant. Somebody might have a sizeable number of edits that are just small typo fixes, but then they discover something they like is being nominated for deletion, at which point they'll shout, for the first time, "Don't delete this article—it's my favourite!". In which case, before you chuckle and throw a bunch of incomprehensible tag soup at them, it might be worth considering that they simply haven't done as many AfDs as you have, so aren't familiar with how they turn out. Hells bells, you could even try to fix the problem for them.
Users occasionally disagree or do things that are technical violations of The Rules™️. We should avoid rancor among good faith contributors by agreeing to disagree or overlooking minor violations. Sometimes the damage from formal dispute resolution is greater than any potential benefit—you might be able to recite the entire set of speedy deletion criteria standing upside down blindfolded in shark infested custard, but the newbie whose talk page you just stuck a big fat template on certainly can't, and may need a sympathetic and calm word before they convince themselves that Wikipedia isn't worth the bother. In that case it is much better to let go of disputes.
- Wikipedia:Drop the stick and back slowly away from the horse carcass
- Wikipedia:Don't bite the newbies
- Wikipedia:Advice for hotheads