Philippe is (apparently) referring to higher-level protocols for markup of hieroglyphic text. See, e.g., Table 14-10 and Figure 14-2, p. 489 in Section 14.18, Egyptian Hieroglyphs in TUS 6.2:
http://www.unicode.org/versions/Unicode6.2.0/ch14.pdf Similar kinds of higher-level protocols are envisioned for other complex scripts currently under ballot, including Duployan families of shorthand and Sutton SignWriting. There are just some writing systems and notational systems whose complexity makes it inadvisable to encode them *entirely* as plain text systems. Some aspects of their behavior are better modeled by markup systems (or other systems) at a level above the plain text encoding, once a sufficient set of atomic elements for the system have been encoded as characters. The general concept here should not be unfamiliar to Unicode aficionados, as this is the approach long advocated for the representation of mathematical expressions. --Ken > > And even without changing anything to existing UTF's, strings of > > characters taken from a smaller block in the supplementary planes may > > be used to implement these large extensions (after all this is already > > what is happening with hieroglyphs). > > I don't understand what this means.
