Question regarding YouTube and the Forum Rules

[Keks]

I have a question about YouTube links and the Forum Rules.

General rules

• It is strictly prohibited to discuss websites, techniques, software and any and all methods that can be used to duplicate, acquire or otherwise access copyrighted and copy protected material except via approved methods by the copyright holders (Blu-ray, DVD, iTunes, digital on-disc copies etc). This includes any and all all variations of disc copying software, torrents and any and all technologies that are available or may become available in the future for these purposes. This also includes any other form of illegal or unethical behaviour for example the unauthorised reproduction of copyright material and trademarks. Any breach deemed serious enough will be forwarded to the relevant authorities.

So, from what I've found and read, posting YouTube links is okay.
But what if I link to a trailer/teaser/preview/music video/or whatever on YouTube, that was uploaded by a 3rd party/private person?
How should one know if these are unauthorised or tolerated by the owner/author? I mean, you could argue that it is tolerated by the owner/author, because it wasn't taken down by YouTube? Once such videos claimed by the owner/author, the video would be gone anyway.
So my question now, is it against the Forum Rules, or is it tolerated to post such YouTube links?
PS: In the Forum Rules it says "all all".