The IUCr Policy on the Use of the Crystallographic Information File (CIF)

The Crystallographic Information File (Hall, Allen & Brown, 1991) is, as of January 1992, the recommended method for submitting publications to Acta Crystallographica Section C. The International Union of Crystallography holds the Copyright on the CIF, and has applied for Patents on the STAR File syntax which is the basis for the CIF format.

It is a principal objective of the IUCr to promote the use of CIF for the exchange and storage of scientific data. The IUCr's sponsorship of the CIF development was motivated by its responsibility to its scientific journals, which set the standards in crystallographic publishing. The IUCr intends that CIFs will be used increasingly for electronic submission of manuscripts to these journals in future. The IUCr recognises that, if the CIF and the STAR File are to be adopted as a means for universal data exchange, the syntax of these files must be strictly and uniformly adhered to. Even small deviations from the syntax would ultimately cause the demise of the universal file concept. Through its Copyrights and Patents the IUCr has taken the steps needed to ensure strict conformance with this syntax.

The IUCr policy on the use of the CIF and STAR File processes is as follows:

• 1 CIFs and STAR Files may be generated, stored or transmitted, without permission or charge, provided their purpose is not specifically for profit or commercial gain, and provided that the published syntax is strictly adhered to.

• 2 Computer software may be developed for use with CIFs or STAR files, without permission or charge, provided it is distributed in the public domain. This condition also applies to software for which a charge is made, provided that its primary function is for use with files that satisfy condition 1 and that it is distributed as a minor component of a larger package of software.

• 3 Permission will be granted for the use of CIFs and STAR Files for specific commercial purposes (such as databases or network exchange processes), and for the distribution of commercial CIF/STAR software, on written application to the IUCr Executive Secretary, 2 Abbey Square, Chester CH1 2HU, England. The nature, terms and duration of the licences granted will be determined by the IUCr Executive and Finance Committees.

In summary, the IUCr wishes to promote the use of the STAR File concepts as a standard universal data file. It will insist on strict compliance with the published syntax for all applications. To assist with this compliance, the IUCr provides public domain software for checking the logical integrity of a CIF, and for validating the data name definitions contained within a CIF. Detailed information on this software, and the associated dictionaries, may be obtained from the IUCr Office at 5 Abbey Square, Chester CH1 2HU, England.