Am 05.11.2015 um 23:11 schrieb Ilya Zakharevich:
First of all, “reserved” means that they have no meaning. Right?
Almost. “Reserved” means that they have currently no meaning but may be assigned a meaning, later; hence you ought not use them lest your programs, or data, be invalidated by later amendmends of the pertinent specification. In contrast, “invalid”, or “ill-formed” (Unicode term), means that the particular bit pattern may never be used in a sequence that purports to represent Unicode characters. In practice, that means that no programm is allowed to send those ill-formed patterns in Unicode-based data exchange, and every program should refuse to accept those ill-formed patterns, in Unicode-based data exchange. What a program does internally is at the discretion (or should I say: “whim”?) of its author, of course – as long as the overall effect of the program complies with the standard. Best wishes, Otto Stolz
