For each reflection class, the number of significantly intense
               reflections (see _reflns.threshold_expression) in the REFLN
               list (not the DIFFRN_REFLN list). This may include Friedel-
               equivalent reflections (i.e. those which are symmetry-equivalent
               under the Laue symmetry but inequivalent under the crystal
               class)  according to the nature of the structure and the
               procedures used. Any special characteristics of the reflections
               included in the REFLN list should be described using the item
               _reflns.details.