Accordingly, Balsa's base language is "ProtoSMILES," a SMILES protolanguage. ProtoSMILES was identified through a process of elimination that started with every SMILES document ever published and every SMILES software implementation. The field was narrowed through two restrictions: (1) the source must be authoritative; and (2) the source must be publicly accessible. "Authoritative" in this context means that the source was created by either Weininger himself or Daylight, who alone can speak most authoritatively about what SMILES is. The requirement for public accessibility ensures that claims of compatibility can be tested. The following documents were identified as candidate ProtoSMILES sources: