I agree that this should be relaxed for VS15 and VS16. For example, the current draft version of UTR #51 even suggests that this be done for three sequences that can not get variation sequences defined until Unicode 10.0.
Would you please write a proposal document or send a note through http://www.unicode.org/reporting.html? Thanks, Roozbeh On Thu, Aug 18, 2016 at 3:20 AM, Christoph Päper < [email protected]> wrote: > While VS1–VS14 (and VS17–256) are used for more or less arbitrary variant > selection (VS4–VS14 are actually still unused), VS15 and VS16 have > conventional de-facto semantics: select text style or emoji style. > StandardizedVariants.txt explicitly claims, referring to Section 23.4 of > Unicode 9, that implementations must ignore VSs that don’t form a > standardized or ideographic variation sequence <http://unicode.org/Public/ > UCD/latest/ucd/StandardizedVariants.txt>: > > > Standardized variation sequences are defined in this file. > > Ideographic variation sequences are defined according to the registration > > process specified in UTS #37, and are listed in the Ideographic > > Variation Database. Only those two types of variation sequences > > are sanctioned for use by conformant implementations. > > In all other cases, use of a variation selector character does > > not change the visual appearance of the preceding base character > > from what it would have had in the absence of the variation selector. > > > > For more information on standardized variation sequences, > > see Section 23.4, Variation Selectors, > > in The Unicode Standard, Version 9.0. > > > Can this be relaxed for VS15 and VS16? > Unlike VS1–VS3 they don’t operate on arbitrary glyph differences but on > the actual Unicode property `Emoji_Presentation`. <http://www.unicode.org/ > Public/emoji/4.0/emoji-data.txt> >
