Looks like that there are 'some' IEC-62056-21, that does not include the 0-1: (or 0-0:) as prefix in the data-lines - probably this can be read from a flag/bit - in any case the new Version will check, if the 2'nd chat is a - and the 4'th is a : and if this is not the case, but the line also contains a *a ( and a ) the default prefix 0-1: is added and then the data line will be parsed... Looks like a cheat - but seams to work fine... KISS at it's best!
Details see: #55