Re: In defense of Plane 14 language tags (long)

From: David Hopwood (
Date: Tue Nov 05 2002 - 12:36:23 EST

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    David Starner wrote:
    > On Mon, Nov 04, 2002 at 06:45:26PM +0100, Dominikus Scherkl wrote:
    > > I found the arguments quite convincing - why deprecate the tags?
    > > Noone has till now brought an argument to deprecate them...
    > Because it's been a long standing discussion on this list. The argument
    > against them is that they're stateful characters that many text
    > processes will have to go to filter out (which, no matter how simple, is
    > another complexity to already complex Unicode text processing),

    There are plenty of other characters that need to be filtered by the same
    processes. Deprecating plane 14 tags won't fix processes that need to
    filter ignorable characters but that don't do so.

    > that just plain won't be supported most places,

    Why is this a problem that requires them to be deprecated?

    > are totally pointless most places,

    So don't use them where they are pointless.

    > and where they aren't pointless, can and should be carried by a
    > higher-level protocol.

    This is not a strong enough argument to support deprecation, IMHO.

    Note that if deprecation implies no longer treating these characters
    as ignorables, then that causes new software that sees existing data using
    plane 14 tags to break (to some extent; probably not fatally). OTOH, if
    deprecation does not imply treating plane 14 tags as ignorables, then
    nothing is gained: the complexity of filtering is still there, but the
    characters can't actually be used.

    - --
    David Hopwood <>

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