Why does Unicode contain whole alphabets of “italic” or “bold” characters in Plane 1?
It would have provided too much flexibility, and would have tempted people to use such characters to create “poor man’s markup” schemes rather than using proper markup such as SGML/HTML/XML. The mathematical letters and digits are meant to be used only in mathematics, where the distinction between a plain and a bold letter is fundamentally semantic rather than stylistic. [JC] Q: Wouldn’t it have made more sense to simply have introduced a few new combining characters in Plane 0, such as: “make bold”, “make italic”, “make script”, “make fraktur”, “make double-struck”, “make sans serif”, “make monospace” and “make tag”? A: This would have achieved the same effect (and with the same space requirements too, at least for things like “bold uppercase A” in UTF-16). One could have also made other characters bold too, or create combinations of the attributes not currently represented. However, it would have provided too much flexibility at the character encoding level and would have duplicated,
