The requirement that genuflection take place on both knees before the Blessed Sacrament when it is unveiled as at Expositions (but not when it is lying on the corporal during Mass) was altered in 1973 with introduction of the following rule: "Genuflection in the presence of the Blessed Sacrament, whether reserved in the tabernacle or exposed for public adoration, is on one knee." "Since a genuflection is, per se, an act of adoration, the general liturgical norms no longer make any distinction between the mode of adoring Christ reserved in the tabernacle or exposed upon the altar. The simple single genuflection on one knee may be used in all cases." However, in some countries the episcopal conference has chosen to retain the double genuflection to the Blessed Sacrament, which is performed by kneeling briefly on both knees and reverently bowing the head with hands joined.