> From: ltru-bounces at lists.ietf.org [mailto:ltru-bounces at lists.ietf.org] On Behalf Of > John Cowan > As long as everything is cased consistently, there is no problem, but if someone > uses anomalous casing, these would become a problem under your proposal. > I propose therefore that only zero/oh, one/eye, and one/ell be treated as > confusables; these could arise only in variant subtags. As John notes, there isn't an issue for subtags from ISO source standards when casing conventions are applied, though there certainly could be when they are not -- e.g. "ia" and "la" in ISO 639-1 -- but we don't want to prohibit such on the basis of failure to apply casing conventions: a security-conscious app *should* apply the casing conventions if displaying these tags in a UI. As John also notes, zero/Oh, one/Eye and one/el issues can arise for variants, and we should ensure that they are prevented. They can also arise for the registered-lang subtag, and that should also be prevented. The registered-lang subtags is also susceptible to the el / "Eye" issue since there are no casing conventions for this subtag. I think we should be adding prevention for that as well. Since extensions cannot be interpreted without reference to other RFCs, I don't think we need to worry about homographs within extensions. Peter Constable _______________________________________________ Ltru mailing list Ltru at lists.ietf.org https://www1.ietf.org/mailman/listinfo/ltru
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