Document variable names need to be all ASCII

[積丹尼 Dan Jacobson]

$ e哈=1
bash: e哈=1: command not found
OK, but on man bash is it ever mentioned that a variable name must be all ASCII?

ENVIRONMENT
       When a program is invoked it is given an array of  strings  called  the
       environment.   This  is  a  list  of  name-value  pairs,  of  the  form
       name=value....

PARAMETERS
       A parameter is an entity that stores values.  It can be a name, a  num‐
       ber, or one of the special characters listed below under Special Param‐
       eters.  A variable is a parameter denoted by a name.  A variable has ...