Is it "captive" or is it "wild"?
The line on where to mark things captive versus wild has been debated often on the forums, and still seems to cause a lot of confusion. I hope this will clarify matters somewhat.
At the basic level:
Captive = an organism that exists in a place and way that a human intended. Examples would be a potted plant, a household pet, or livestock in a pasture.
Wild = something that lives in a place where humans did not (intentionally) put it. A wild bird, a tree in the forest, a mushroom - these are all obviously wild.
Here's where it gets more complicated, and where a lot of people get confused:
Things growing ON captive things - plant pathogens often get marked as captive because they're growing on a captive plant. But unless you deliberately inoculated your houseplant with powdery mildew fungus to see what it would do, the mildew would be wild. Same goes with unintended organisms in your house or sprouting in your garden bed. These are often particularly important to NOT mark as captive, because they can indicate new outbreaks of diseases or invasive species, and they become hidden from view when marked captive.
Brief captivity - if you capture a bug in a jar so you can take a photo, or pick up a lizard, it is still "wild" - you are still in the spot that you found the creature, and it was at that location on its own. The fact that you have briefly interrupted it doesn't require it to be marked captive.
Samples brought home: Some organisms, such as certain fungi, just can't be identified in the field, or you need access to equipment you don't have with you. If you take a sample home, examine it, photograph it, and upload those photos, (and the specimen hasn't gone through any significant changes since you found it) it should still be considered wild, but you should upload it with the date and location you found it in originally, NOT where you took it to examine.
However, if it has changed substantially - say you found a cocoon in the woods, but when you brought it home and put it in your nice warm house for 2 days, it hatched into a moth - the moth should be considered technically captive, because it was your influence (putting it somewhere warm) that caused it to hatch at a time when it probably wouldn't have otherwise.
Some people take a picture of the cocoon in its original setting, and then add the additional images of the moth to that same observation, with a note about the adults being reared in captivity. Some people prefer to make a second, captive, observation of the adult moth and put a link to that in the cocoon observation. Either approach is fine.
A tree that was planted in landscaping is Captive, but if that tree sheds seeds and those sprout, the new seedlings are "wild". This goes for restoration plantings as well.
Gray areas:
A feral cat is considered "wild" and should be marked as such, while a pet cat is "captive" - even if they're sitting side by side hanging out in the same field. This seems weird, but it's important to know if feral cats can survive independently in an area. Some places might be fine for domestic cats, but cats living on their own outdoors don't survive.
Similarly, a pet dog that got abandoned on a roadside, stayed in that same spot, and eventually died, would be still considered captive - it was exactly where a human had intended it to be. But if that same dog took off running and wound up surviving in the woods a few miles away, it would be "wild".
Escaped pets should generally be considered wild, especially because there's no way of proving that they were pets, or how they got there. An unusual animal wandering around loose in an area should be taken as just that - making assumptions about how it got there doesn't do anybody any favors.
It could be an abandoned pet, or it could be the start of a new population of a non-native species. Or it could be a species known to harbor some disease that might spread to whatever predator snaps it up. But in any case, it's interacting with the rest of the natural environment, and ignoring it would be a mistake.
I do make an exception for "temporary escapees" - stray cattle that wander out of a broken fence, the neighbor's tortoise that gets apprehended halfway down the street, well-cared-for and collared dogs that happen to be currently unsupervised, etc. If it's obvious they were recently captive and will become so again very quickly, I think it's fine to ignore them. But this generally requires some personal knowledge of the area and animals in question, so I'll go with whatever the observer's wish is on those.
Another gray area is garden plants that volunteer from seed year after year, but only in cared-for conditions of a garden bed, and they do not survive outside of that location. There are valid arguments for both sides on that one, and I haven't decided which one I'm in favor of.
