ble name. It is safer to limit this string to the letters in the range a-z and underscores.
default... single character. It is safer to choose a single letter (lower or upper case) in the ASCII standard.
... or: a string. It is safer to choose a sequence of letters in the ASCII standard, separated by underscor... in the ranges A-Z, a-z, 0-9 are allowed as option letters.
mbfl_getopts_isbrief_with string optnam
