Cleavage, swimsuits, and underwear (including pantyshots) should be rated S 99% of the time. If it's clearly visible from the thumbnail, or notable enough to be worth tagging, then it should probably be rated S.
The exceptions would be when it's barely visible and in a context with zero fanservice or sex appeal. This is rare because anime is filled with fanservice and sex appeal. Frankly I don't trust most users to be a good judge of this, since most users here are so desensitized to sexiness in anime they don't recognize it when they see it. That's why the default assumption should be that it's rated S.
There is some extra leeway for things like chibis and comics, but just because something is a chibi doesn't automatically mean it's rated G.
Of your examples, post #5275256 and post #5221479 are perfect examples of things that absolutely should not be rated G. The first because it has an underage character posing in a bikini while being ogled by a male. The second because it has a loli-like character in a skintight school swimsuit. It's very important that anything that could be construed as the sexualization of minors, even in the slightest way, is not rated G. Anime fans may not see it that way, but that's not always how it appears to outsiders.
On a related note, I just noticed the following line was axed from the article since I last checked it:
howto:rate between 22-05-23 and 22-06-08
Is this not the case anymore and these now do disqualify a post from being G-rated, or should I not read anything into that change?
I removed that line because I didn't write it and I don't want people using it as an excuse to push the boundaries.
I hesitate to say anything along the lines of "it's okay to show a little bit of skin sometimes" because you if give people an inch, they'll take a mile. That's what happened to the old rating system. The rule used to be that "tasteful" swimsuits and "tasteful" lingerie were safe and the rest were questionable. That eventually turned into "all swimsuits and lingerie are safe by default unless you can see the nipples". Then that turned into people rating micro bikinis so small they didn't even cover the areolas as """safe""" (post #5428068) because technically you couldn't see the nipples. Taggers want simple rules and don't do well with nuance.
The rules are strict because I know people will always push the boundaries, so the rules start from a baseline of "cleavage and swimsuits are always rated S" because in practice I know that will turn into "cleavage and swimsuits are rated S 99% of the time", which is the outcome I want.
