stupid format question

[Urdaneta, Alfonso E (N-Summitt Technologies)]

I have an IEEE language definition that looks like so:

noun-field:
    { noun | 
      noun-name } [ "USING" label-identifier ];

now my first thought is that in bisonland this would look like so (I have
omitted dependencies)

noun_field:
    { noun | noun_name }
    | noun_field USING_TOKEN label_identifier
    ;

but then this will match

  noun USING label USING label USING label....

which I don't want.

I couldn't find anything in the docs that said anything about how to limit
sequences.

Can anyone point me in the right direction ?

Thanks,

Alfonso.