I was careful. :)

> representable in a finite number of digits or bits

Implying a digit-based representation.

> the Unicode string "√5" is representable as 4 UTF-8 bytes

As the other person pointed out, this is representing an irrational number unambiguously in a finite number of bits (8 bits in a byte). I fail to see how your original statement was careful :)

> representable in a finite number of digits or bits