Carl Brown said: > > U+FDD0 to U+FDEF are also noncharacters that represent a range that can be > used by font rendering engines as an internal working set. An urban legend seems to have sprung up here. So once again, I assure everyone that there are no alligators living in the sewers resulting from all those people flushing their baby alligators down the toilet. U+FDD0 to U+FDEF are also noncharacters. Period. They can, of course be used by font rendering engines as an internal working set. But they can be used for any other internal purpose anyone sees fit to use them for. They could serve as anchors to 32 kinds of embedded objects. They could serve as virtual weights for a collation implementation. They could serve as intermediate code points for a roundtrip mapping. Or... The important thing is that they cannot be interchanged or publicly interpreted. Period. The fact the U+FDD0 to U+FDEF is a range that occurs in the middle of a bunch of Arabic presentation forms is irrelevant to their status as noncharacters. It was simply inventive use of scarce code points on the BMP and has nothing whatsoever to do with putative functionality of the noncharacters. --Ken
