prefix patterns cannot be defined as constants

Hi there! Just noticed that (shorthand and long) prefix patterns cannot be defined as constants. During a quick search I couldn't find this behaviour documented, so maybe it might be considered a bug? Example: define my_const = fc01:2345::/48+; ... returns a syntax error. As does: define my_const = fc01:2345::/48{48,128}; Best regards, Kai