Re: ct, fj and blackletter ligatures

From: William Overington (WOverington@ngo.globalnet.co.uk)
Date: Sat Nov 02 2002 - 02:18:43 EST

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    The matter of ligatures arises fairly often in this discussion forum, often
    in relation to German Fraktur, but also in relation to English printing of
    the 18th Century and the use of fj in Norwegian.

    In relation to regular Unicode the policy is that no more ligatures are to
    be encoded. My own view is that this should change. However, that is
    unlikely to do so.

    Earlier this year, following from a posting about Fraktur ligatures, I
    produced some encodings for ligatures using the Private Use Area. I have
    published them on the web at the following place.

    http://www.users.globalnet.co.uk/~ngo/golden.htm

    These are my own Private Use Area code point allocations for various
    ligatures. They are not in any way a standard yet they are a consistent set
    which may be useful to those who wish to use them. The only use I know of
    any of them in a published font is in the Code2000 font, produced by James
    Kass. James uses the code points of this set for ct, fj and ffj in his
    Code2000 font.

    I feel that it might well be of interest to you, for your background
    knowledge, to have a look at the encodings which I have produced, yet I
    mention that these Private Use Area encodings are a matter of some
    controversy. Using them could lead to documents existing which could not be
    text sorted alphabetically, or spellchecked. However, if someone is just
    wishing to produce a print out of some text with some ligatures in the text,
    then the golden ligatures collection can be useful. There seems to be a lot
    of theoretical possibilities for doing ligatures with Unicode fonts using
    advanced font technology using the latest computers, yet if, say, someone
    wants to set and print out a page of Fraktur, that possibility does not
    seem, as far as I know, to be a practically achievable result at the present
    time using a piece of text encoded in regular Unicode using a font which
    uses only regular Unicode encoding. Indeed, it seems more likely that one
    would need to use a Fraktur font with ligatures encoded with a code number
    below 255, that is, a font which is not Unicode compatible. The golden
    ligatures collection is Unicode compatible, though, as I say, it is not a
    standard. It is just one person's self-published writing. I like to think
    of it as an artform, much as if I had produced a painting and placed a copy
    of the painting on the web. That is, it exists, it may be interesting to
    people, yet it does not in any way prevent anyone else from doing something
    different and it does not require anyone else to take any notice of it, yet
    it is a cultural item in the world of art.

    So, it depends what one is wanting to do. If your enquiry is solely in
    relation to formal encoding of ligatures in regular Unicode, then the golden
    ligatures collection will be of no use to you. However, if you are
    producing a black letter font as part of your studies and would like to
    encode ligatures, then the golden ligatures collection might perhaps be of
    interest to you. For example, if such a font were encoded using advanced
    font technology, then the golden ligatures collection code points would not
    be the way to approach the problem, though they could, if you so chose, be
    used to provide an additional way of accessing the glyphs for people who
    were trying to produce printouts using, say, a Windows 95 or a Windows 98
    system. If, however, such a font were produced as an ordinary TrueType
    font, then in order to access the ligature glyphs you would need code points
    in order to access the glyphs, one code point for each glyph. In order to
    be Unicode compatible, those code points would need to be in the Private Use
    Area range of U+E000 to U+F8FF. There is essentially complete freedom of
    choice as to which code points to use, though the lower part is perhaps best
    due to the suggestions about Private Use Area usage in the Unicode
    specification. However, the golden ligatures collection of code points is
    there for your consideration if you wish.

    Within my collection of code point allocations, ct is U+E707, fj is U+E70B,
    ch is U+E708, ck is U+E709, tz is U+E70F.

    These are all in the following document.

    http://www.users.globalnet.co.uk/~ngo/ligature.htm

    The ffj is encoded at U+E773 in the following document.

    http://www.users.globalnet.co.uk/~ngo/ligatur2.htm

    There are some black letter ligature encodings including pp at U+E76C and
    ppe at U+E77E in the following document.

    http://www.users.globalnet.co.uk/~ngo/ligatur5.htm

    The Private Use Area is described in Chapter 13, section 13.5 of the Unicode
    specification. There is a file named ch13.pdf available from one of the
    pages in the http://www.unicode.org website.

    The main index page of our family web site is as follows.

    http://www.users.globalnet.co.uk/~ngo

    William Overington

    2 November 2002

    -----Original Message-----
    From: Thomas Lotze <thomas.lotze@uni-jena.de>
    To: unicode@unicode.org <unicode@unicode.org>
    Date: Friday, November 01, 2002 12:28 PM
    Subject: ct, fj and blackletter ligatures

    >Hi,
    >
    >the alphabetic presentation forms starting at UFB00 contain a number of
    >ligatures for latin scripts, among them the more common ones like fi and
    >fl, but also rather exotic ones like st.
    >
    >However, I find there are a couple of other ligatures in use, namely the
    >ct ligature (for instance to be found in Adobe Garamond), the fj
    >ligature, and a couple of ligatures common in blackletter typesetting:
    >among them ch, ck and tz. Would it be a good idea to propose these
    >ligatures for inclusion in Unicode?
    >
    >Cheers, Thomas
    >
    >--
    >Thomas Lotze
    >
    >thomas.lotze at gmx.net http://www.thomas-lotze.de/
    >
    >



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