Section 5.3.3.3.2. Options

As already mentioned, the user could modify the detailed mode of operation of the program. Any or all of the `initial', `dictionary' or `other' checks could disabled.

The `dictionary' checks could be modified by the user through the `Options' button of the main control window. The CIF dictionary for validation could be specified; the dictionary itself had to be translated from a source file in DDL format to a Python data structure.

The types of dictionary-based validation supported by the program were:

(i) List Status (checking whether a data value should be included in a looped list),

(ii) Limited Enumeration Options (checking that a data value is one of the permitted codes where such a constraint exists),

(iii) Incorrect Enumeration Case [a special case of (ii), where a data value matches a permitted code except for incorrect alphanumeric case],

(iv) Enumeration Range (the data value falls outside the range permitted),

(v) Value Type (numb or char) (the data value has the wrong type),

(vi) List Link Parent (a data item is present within the data block, but its mandated parent item is not – for example, the data item _atom_site_aniso_label should not be present without its parent data item _atom_site_label),

(vii) List Reference (the required data name used to reference the loop in which the current data name appears is missing),

(viii) Esd Allowable (a data value appears to have a standard uncertainty value where one is not expected).

The user could also supply the program with a list of data names that do not appear in the validation dictionary but for which no warning message should be raised. The program normally flagged such nonstandard data names as possible errors and suggested the possible form of a standard data name that might have been intended. This was useful in catching misspellings of additional data items entered by hand.

The program could also be run in a batch mode when the objective was to work through a large volume of CIF data and identify the data blocks that require attention. This mode of operation is particularly useful in databases or publishing houses. In this mode, input is from a named file or from the standard input channel; output is written to standard output or redirected to a results file. The operation of the program may be controlled by the application of various command-line flags.