Re: Hypersurrogates

From: William_J_G Overington (
Date: Fri Aug 28 2009 - 12:21:44 CDT

  • Next message: Kenneth Whistler: "Re: Hypersurrogates"

    This post refers to two posts in the archive, namely the following.

    In the post, I wrote as follows.


    The calculation of the registerable private use area
    character codepoint would be by extracting n bits from the
    high hypersurrogate, multiplying by 2 to the power of n,
    then extracting n bits from the low hypersurrogate and
    adding that value, followed by adding hexadecimal
    110000. The value of n herein mentioned would be fixed
    during the encoding process of the Unicode Consortium: maybe
    a value such as 14 or maybe 15 or even 16.

    end quote

    I have thought further on this matter and am now thinking that a good idea would be to encode high hypersurrogates as U+A0000 to U+AFFEE and low hypersurrogates as U+B0000 to U+BFFFF. The value of n would thus be 16.

    In mention is made of deprecated private-use areas.

    I write to ask please as to whether anyone can please state what is the present situation in relation to Unicode and in relation to ISO as to whether there are or are not any permanent rulings as to which codes beyond U+10FFFF could or could not be used in a future version of the Unicode Standard?

    If the code space were extended, which could, in my opinion, be useful for such purposes as registering logos and registering Japanese personal characters so that they could then be used in electronic documents that could be archived in libraries and searched electronically, then various developments in software would be needed. For example, a future version of WordPad might be able to use Alt codes for such characters and some future fonts would be capable of including glyphs for such characters.

    William Overington

    28 August 2009

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