default format to "0" and do default handling afterwards
default format to "0" and do default handling afterwards

LATER: we might want a format AMBIX_UNKNOWN=-1

CID:22446

iem-projects/ambix,umlaeute/ambix,iem-projects/ambix,kronihias/libambix,umlaeute/ambix,umlaeute/ambix,kronihias/libambix,iem-projects/ambix