Core dictionary (coreCIF) version 2.4.5
The number of Friedel pairs measured out to _diffrn_reflns_theta_full. divided by the number theoretically possible (ignoring reflections in centric projections and systematic absences throughout). In contrast to _reflns_Friedel_coverage this can take values in the full range 0 to 1 for any non-centrosymmetric space group, and so one can see at a glance how completely the Friedel pairs have been measured. For centrosymmetric space groups the value would be 0/0 and so would be given as '.'.
The permitted range is 0.0 -> 1.0