> The Unicode Standard is a plain text standard, *not* a > text layout standard. See Section 2.9 of The Unicode > Standard, Version 4.0 for what the standard has to say > on this. > > The extent of directional layout required of a *plain text* > standard is the bidirectional algorithm, which sorts > out how a (horizontal) *line* of text is laid out when > text of opposite directions is mixed. Beyond that, you > are on to higher level protocols for textual layout. > Those are out of scope for the Unicode Standard. > > --Ken
And even for a "(horizontal) *line* of text"
If you have rich text, so you can choose to use either the bidi algorithm or the rich text facilities to do the bidi. Then the rich text facilities are preferable?
Right?
Not necessarily. Depends a lot on what you meant to say by 'either / or' here. Please read the relevant text on Higher Level Protocols in the latest edition of UAX#9
http://www.unicode.org/reports/tr9
It's very clear about the role of higher level (rich text) protocols.
A./
