International
Tables for Crystallography Volume G Definition and exchange of crystallographic data Edited by S. R. Hall and B. McMahon © International Union of Crystallography 2006 |
International Tables for Crystallography (2006). Vol. G. ch. 2.2, p. 29
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(34) As an archival file format, the CIF specification is expected to change infrequently. Revised specifications will be issued to accompany each substantial modification. A CIF may be considered compliant against the most recent version for which in practice it satisfies all syntactic and content rules as detailed in the formal specification document. However, to signal the version against which compliance was claimed at the time of creation, or to signal the file type and version to applications (such as operating-system utilities), it is recommended that a CIF begin with a structured comment that identifies the version of CIF used. For CIFs compliant with the current specification, the first 11 bytes of the file should be the stringimmediately followed by one of the white-space characters permitted in paragraph (22).