GITNE (2021-04-15 09:49:31+00:00): >> The phone is a public phone, not a private phone.
> 
> Not sure why you think so because it's not. In fact, I didn't see a phone inside 
> at all. It must be hidden somewhere behind the counter.
Perhaps it is. 
>> The same applies to “7 days open” on the sign. As an observer you are allowed 
> to make assumptions, regardless whether you are on site or sourcing data from 
> imagery.
> 
> Making reasonable assumptions, like "the phone number on the sign is probably 
> correct" is fine, although you should even be wary of doing this in areas that 
> you are not familiar with (anyone native to Oregon would know that a 7-digit 
> number is not valid).
I am and I was aware that the phone number is probably not valid. Nevertheless, it is what the sign says. Besides, exceptions may still exist even after renumbering has been completed. As a mapper for OSM, my responsibility for verifying the validity of most data basically ends with reading what a sign says or what you can seen in an image. If I can verify data more thoroughly or to further ends then fine, I can map more accurately. So, it is what it is.

Assuming that “open 7 days" means 24/7 is a poor assumption.

That’s your opinion but I think it is still a reasonable assumption if you happen to know that most convenience stores in the US (and around the world) are open 24/7. Technically, if read through the eyes of a lawyer then sure, “open 7 days” does not necessarily include 24/7.

>> Bus stops are fully accessible when people on wheelchairs can get to the bus 
>> stop without obstacles, that is just roll through. The same applies to boarding 
>> and disembarking a bus. The bus stop does not seem to have been outfitted with a 
>> ramp or any other device to enable wheelchair users to roll on board.
> 
> Where did you get this idea from? The wiki says "Use this tag to mark a feature 
> in the United States as compliant with the Americans with Disabilities Act 
> (ADA)." To the best of my knowledge, the ADA doesn't require the stop to have a 
> ramp to the bus.
Right, because ADA is not concerned with any particular pieces of infrastructure (at least not directly) but with organizations, businesses, and state authorities. So, you have to make a distinction between a transportation entity (or agency, network, etc), that is the bus fleet operator, who serves any particular bus stop and a bus stop as a physical piece of infrastructure. ADA does not require putting compliance stickers neither on bus stops (or buildings) nor on businesses or organizations. Simply put, an entity is ADA complaint as long as nobody complains or an oversight authority does not step in. But, this is not exactly how OSM works. OSM does put compliance stickers on physical objects in its database, by mapping with three different `wheelchair` values. Labeling with any particular value depends on the properties of the object. For example on buildings, `wheelchair=limited` usually means nothing more than that the entrance has a step which potentially can be overcome by most wheelchair users on their own. You can be more specific, map the entrance separately and tag it with `wheelchair=limited` and map the building with `wheelchair=yes` where building amenities might be accessible but not its entrance. On bus stops however, `wheelchair=limited` means that you can get to the bus stop but once you are there, you cannot expect to find a ramp or a raised curb there and you are at the mercy of the bus (and driver) to pick you up (or that there is some sort of obstacle to access the bus stop but otherwise getting on and off the bus is smooth). Basically, it means that you are gambling unless you are sure that the route is served by an accessible bus.

> People in wheelchairs can get to the bus stop because the curb 
> is lowered on both sides. If there is no ramp, the bus is not wheelchair 
> accessible, but the stop still is.

This is only half of the story to a bus stop. As you said yourself, the bus stop itself may be wheelchair accessible but the bus may not (or vice versa). And, as a wheelchair user when you look at a bus stop you are not only interested in getting to the bus stop but also in getting on and off the bus. This is why in OSM terms `wheelchair=*` is more about practical accessibility, not so much about a legal or technical standard. Again, OSM sources its data from observable reality like signs or missing ramps, not from legal standards.

> I've never even heard of having such a ramp at the bus stop rather than on the 
> bus. I can't imagine any practical way to make that work, since the bus would 
> have to stop in a very precise place for the ramp to extend inside. If you know 
> of anywhere that this exists, I'd like to hear about it. It certainly doesn't 
> exist in Portland.
Just because you have never heard, seen, or cannot imagine something does not mean that it does not exist. Generally speaking, this a bad premise to operate on.
Look at “South Lowell & Bond”: https://www.mapillary.com/map/im/QqYwsTwqdVVZd9IWiefGMw
Although this stop is primarily served by street cars (a `tram` in OSM terms), it is fitted with a raised curb. So, it can also be served by buses without a ramp. This stop has a modern raised curb but there are also older style raised curbs in Portland, like at “West Burnside & Burnside Bridge”.
See here: https://www.mapillary.com/map/im/E0iJuaxW1-NCTh-1-Eyl_w
There are many more similar examples in Portland (and around the world).