макропроцессор (macro processor)
Обоснование (Rationale)
Historic System V-based behavior treated "${" in a macro
definition as two literal characters. However, this sequence is
left unspecified so that implementations may offer extensions
such as "${11}" meaning the eleventh positional parameter. Macros
can still be defined with appropriate uses of nested quoting to
result in a literal "${" in the output after rescanning removes
the nested quotes.
In the translit built-in, historic System V-based behavior
treated '-' as a literal; GNU behavior treats it as a range. This
version of the standard allows either behavior.
