* we extract values for other data which are allele-specific;
* these may be per alternate allele (INFO[key].Number = 'A')
* or per allele including reference (INFO[key].Number = 'R')
* we extract values for other data which are allele-specific;
* these may be per alternate allele (INFO[key].Number = 'A')
* or per allele including reference (INFO[key].Number = 'R')