:laugh: When I was growing up and in school, we were served fish on fridays because of the Catholics who were not allowed to eat meat on that day. Then somewhere along the line the Pope decided it was not a sin anymore to eat meat on friday and lo and behold, we were served burgers. There have been several such changes of mind by the various Popes. Seems they cannot agree with one another either.
Catholics still observe abstinance on Fridays. "It is a traditional doctrine of Christian spirituality that a constituent part of repentance, of turning away from sin and back to God, includes some form of penance, without which the Christian is unlikely to remain on the narrow path and be saved (Jer. 18:11, 25:5; Ez. 18:30, 33:11-15; Joel 2:12; Mt. 3:2; Mt. 4:17; Acts 2:38). Christ Himself said that His disciples would fast once He had departed (Lk. 5:35). The general law of penance, therefore, is part of the law of God for man."
The Church for her part has specified certain forms of penance, both to ensure that the Catholic will do something, as required by divine law, while making it easy for Catholics to fulfill the obligation. So the 1983 Code of Canon Law specifies the obligations of Latin Rite Catholics [Eastern Rite Catholics have their own penitential practices as specified by the Code of Canons for the Eastern Churches].