Battle pet abilities can be… weird. Tooltips can only say so much, and a lot of the details one can know only by trial and error with a little bit of data.
So I thought I’d be worth it to continue what Gemllum has tried once on old US forums – and contain as much info about the abilities as possible.
I can enclose two main goals for the list:
- To have a resource handy to link or quote when a player notices anything odd, or would like to ask “what if?”, and:
- To highlight various events behind the scenes, including how blurry the distinctions between features, oversight and bugs may be, and – laugh as you might – contribute to the feedback.
[The public content being public: don’t exploit, ya troggs. All the worst of the bunch has been reported, and undoubtedly will be again.]
Thus, the way of presentation might look a little jagged, with so many things clumped or not a little arbitrarily, and seemingly obvious things juxtaposed with database terms.
But I am afraid, had I wondered any longer about this, I’d have delayed it even more!
I will be happy to keep updating the contents as long as I can, provided that any given claim can be easily reviewed, and Public Test Realms remain helpful.
While it might be me who maintains the document, it’s a product of shared knowledge of many wonderful people who have been at it for years. Many still there, some no longer – but all mentioned in the preface. 
I’d like to also thank the author of wow.tools, for both the convenience and its eye opening character. Wishing many amazing prospects for the future, and for the legacy to carry on the way you wish it to.
https://docs.google.com/document/d/15pcQC_FnG2MiJ8Z1tOpZh9auZLs8CTRRLCvCKR9CJfo
Please note this is not a balance prompt. It will come, but I believe fixing bugs and clarifying intended behaviour comes first, because otherwise, what are you trying to keep up with anyways?
I guess glaring headscratchers such as “identical abilities with different cooldowns” are fine, and might make a separate list of these later.
Also, please don’t make the discussion too much of a grumpfest, everything is a grumpfest right now, and the local variety of… well, also’s been going for years. 
Anything the forums can’t handle or the topic timed out? I’m in Discord as Remte-EU#8485, and in Xu-Fu’s Pet Guides. I am sure other people will be happy to help, too!