Retention of Blades Test A flush or self-contained receptacle having a 5-15R,5-20R,6-15R, or 6-20R configuration shall be subjected to the retention of blades test described in this Section. Exception: A receptacle having a 1-15R,5-15R,5-20R,6-15R, or 6-20R configuration and not of the flush or self-contained type may instead be subjected to the Retention of Plugs Test, Section 116. Receptacles ha...