The Crystallographic Information Framework provides both a concrete file syntax and an ontology of concepts characterized by specific data names in a family of dictionaries. While the concrete syntax is familiar to crystallographic applications, interoperability requires exchange of information using file syntaxes used in other scientific domains. A full specification is given for CIF-JSON, a JSON schema that affords a clean mapping of CIF semantic data into a well-supported serialization syntax. Several other syntax models are also described, allowing data exchange with macromolecular (PDBML, mmJSON, BinaryCIF) and chemical (CML, MIF) structural sciences. The semantics of the contained data are conserved through mappings of the data names with associated definitions in CIF dictionaries.