Re: Proposal to add standardized variation sequences for chess notation

From: Michael Everson <>
Date: Mon, 3 Apr 2017 22:15:16 +0100

On 3 Apr 2017, at 17:16, Asmus Freytag <> wrote:

>>> The same indirection is at play here.
>> This is pure rhetoric, Asmus. It addresses the problem in no way.
> Actually it does. I'm amazed that you don't see the connection.

I’ve never understood you when you back up into that particular kind of abstract rhetoric.

>>> the oft-stated fact that variation selectors may be ignored.
>> I’m aware of this. I may be wrong, but I believe you advocated for the encoding of variation sequences for mathematics purposes.
> Yes, for those cases where the differences are known to not carry meaning, but where duplicating all fonts or duplicating the characters would have been the wrong solution to allow support for both conventions (e.g. upright vs. slanted integral signs, details of relational operator design, etc.).

The “meaning” of a chess-problem matrix is the whole 8 × 8 board, not the empty dark square at b4 or the white pawn on

The “problem” the higher-level protocol is supposed to solve is the one where a chess piece of one colour sits in an em-squared zone whether light or dark. In lead type this was a glyph issue. Lead type had just exactly what my proposal has: A piece with in-line text metrics, spaced harmoniously with digits and letters, and square sorts with and without hatching.

Standardized variation sequences are the best way to achieve this simply and without needless duplication. :-)

>> Are you saying that the empty white and black squares should use VS but the chess pieces are not? That makes no sense to me at all.
> I'm saying that perhaps it would be appropriate to select M-square glyph variants via a variation selector. That seems a clear-cut glyph *variation* to me. (If this variation is ignored, then the text looks bad, but in a way that is similar to selecting the wrong font - which is a rule-of-thumb way of evaluating whether variation selectors are appropriate).

OK, then you support the part of the proposal that applies VS1 and VS2 to the chess pieces.

> The distinction between white/black background might be of a different nature. If you have arranged everything in a grid with the correct matrix, then the color of the background is perhaps redundant, given that there is a uniform convention for it.

Yes but you still want it to be reasonably legible when the OpenType ligatures fail. I think that this:

is far better than this:
▕□︀□︀□︀♙︁♛︀□︀□︀□︀▏<< Is it the pawn or the queen that’s on the black square?
See? To parse this one you have to remember which of the white squares are the alternating black ones. I don’t consider that as legible as using both 25A1 and 25A8.

The colour of the matrix is NOT redundant for a human reader.

> If you assume the characters will ever be used outside a full grid, then that assumption fails and it will not be possible to restore the intended meaning if the variation selectors are missing. That's a warning flag, that they may not be appropriate for that use.

You can’t assume that they wouldn’t be. All of my examples in §2 of the proposal are in fact outside of a full grid. I think the proposal as it stands ticks the most boxes. (I have changed “black square” and “white square” to “dark square” and “light square” however.

Michael Everson
Received on Mon Apr 03 2017 - 16:15:37 CDT

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