What is our standard target
"We" [PG] do not have a standard target. "We" often pretend that HTML *is* a standard in the first place, and that the HTML that we see rendered on our favorite computer on our favorite browser on our favorite display represents the same results that some other customer is going to see on their favorite computer using their favorite rendering software onto god knows what kind and size of display technology.
(more specifically, what were you testing with)?
I, specifically, was testing on a Kindle Klassic and a Kindle Fire, because the Amazon devices are what most real world people read ebooks on, and they display the most errors in PG book submissions. But I went back and checked on an epub device and didn't find much better luck. And sometimes the Amazon devices actually show better results on PG books than epub readers. Note that the PG/submitter sausage-making chain typically runs: Txt->html->epub->mobi So that the mobi files, as being most derived, are most likely to display the greatest range of errors coming from the entire "PG" process. That and Amazon/mobi made some design decisions that predate modern HTML design rules, and that complicates things. Point being that one *can* write HTML that works pretty much everywhere, but many people insist on writing HTML which only works on their particular favorite flavor of computer. DP in particular has a peculiar strain of HTML writers who are openly hostile to writing HTML in an in-practice portable manner. I have found commercial ebooks render considerably differently in FBreader and Coolreader on Android, not to mention PG books (I almost always have to adjust the default font size on a per-book basis, at the very least). I think there are similar rendering differences between the Kindle, Nook, and Sony readers. Yes but if the HMTL is written correctly the results should work on all of these devices. Well, not that sure about FBreader and Coolreader - I blew them off after brief tests as being hopelessly incomplete.