In 2007 a documentation effort that would become known as OpenSMILES began . OpenSMILES was conceived as "a non-proprietary specification for the SMILES language." Many of the points left open by previous SMILES documentation efforts were addressed. Noteworthy contributions included: the first formal grammar, later adapted to a standard parser toolchain ; many refinements around stereochemistry; and the introduction of "standard form." Absent were detailed procedures for composing and interpreting aromatic features, and a detailed procedure for computing implicit hydrogen count. OpenS-MILES also left several points of syntactic and semantic ambiguity unsettled, while introducing extensions of its own.