But just like you adviced a reference link to the image is not going to consume time so i think i will just input it to avoid such misunderstanding that took place in the above link. Although just like nullius stated in the discussion that the whole issue was all due to grudges held between the two party involve @whitemanwhite @icopress .
Yeah, when in doubt it's always best to take the necessary precautions. However, most users here don't go through those additional steps, and like the quote above generally users don't get punished for it. Nice to see you looking for clarity on it though, it's not a overly discussed thing. Most of the rules can be found in mprep's unofficial rules though, and there's quite a lot of discussion in that thread itself, delving deeper into each rule. That's usually the good to for most of the common sort of rules.
Even if it's not against the rules per say or at least you won't get punished for it. Quoting the source of images that aren't memes is generally a nice thing to do. Especially, when it comes to original content. If it's memes, I mean they've been recycled so many times you wouldn't be able to find the source anyhow.