why is char's sign-ness not defined in C?

Question

The C standard states:

ISO/IEC 9899:1999, 6.2.5.15 (p. 49)

The three types char, signed char, and unsigned char are collectively called th

Answer 1

I suppose (out of the top of my head) that their thinking was along the following lines:

If you care about the sign of char (using it as a byte) you should explicitly choose signed or unsigned char.