In this case though you're adding a 'special' condition for the parser/processor. Of course you could do it but as per the spec its not required - I'm just look

In this case though you're adding a 'special' condition for the parser/processor. Of course you could do it but as per the spec its not required - I'm just looking up the schema now to find the reference. Example is you can * no problem, its expecting only a number for the 'read_next' but with the `-' it's expecting a denomination, otherwise it needs to keep a 'state' as such when moving on from reading a `0` Edit : as pointed out by zarzavat : it does seem to be a bug in the spec in this case.