Please explain the rationale behind the current alphabet

[mimi89999]

Hello,

I noticed that the alphabet contains chars that cause issues with some languages like:

• $ that needs to be escaped in Bash double quoted strings

• &, <, > that can't be included in XML

The alphabet does not contain some other potentially safe chars like: space, ,, ;, _, |, ~

Why the characters that are currently listed in the alphabet where chosen instead of the 6 other possible ones?