UAX #9: applicability of higher-level protocols to bidi plaintext

Shai Berger via Unicode unicode at
Mon Jul 9 17:33:28 CDT 2018

Hello all,

About two and a half years ago, I suggested adding a FAQ about the
applicability of higher-level protocols for bidirectional plaintext, as
specified by -- my suggestion was
to clarify that higher-level protocols can only be applied upon
agreement between all producers and consumers, and that such agreements
effectively mean that the text is "special text" -- no longer plain.

In the time since then, I have been mostly removed from this issue, but
I came back to it recently, to find that my suggested text was
rejected, and instead, two FAQs were added to The first, which is marked by the
HTML anchor bidi7, goes with my understanding and defines a
higher-level protocol as an agreement; but the second, marked as bidi8,
goes the other way, and explains that actually, agreement is not
necessary -- a program is at liberty to "implicitly define an overall
directional context for display, and that implicit definition of
direction is itself an example of application of a higher-level
protocol for the purposes of the UBA".

One result of this is the following scenario: I open my
standard-compliant text editor, and write a line of text (to make
things accessible to a wider audience, I use capitals for right-to-left
English and small letters for normal, left-to-right English; note this
sentence starts from the right):

	SESU RETHO DNA email ROF plaintext REFERP I

I save this line in a text file. Then I display it using my
standards-compliant text viewer, but now it looks like this:

	REFERP I plaintext ROF email SESU RETHO DNA

And this is because my standard-compliant text-viewer chooses to apply
its higher-level protocol and treat the line as a LTR paragraph.

Since bidi8 is a little abstract on this point, and focuses on terminal
windows rather than editors and viewers, I would like to ask:
Does this concrete result represent the intents of the UTC?

Thanks for your attention,


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