Canon 1250 All Fridays through the year and the time of Lent are penitential days and times throughout the entire Church. Nevertheless, pastors and parents are to see to it that minors who are not bound by the law of fast and abstinence are educated in an authentic sense of penance. It is for the conference of bishops to determine more precisely the observance of fast and abstinence and to substitute in whole or in part for fast and abstinence other forms of penance, especially works of charity and exercises of piety. The Church, therefore, has two forms of official penitential practices - three if the Eucharistic fast of one hour before Communion is included. The law of abstinence requires a Catholic 14 years of age until death to abstain from eating meat on Fridays in honor of the Passion of Jesus on Good Friday.
Meat is considered to be the flesh and organs of mammals and fowl.
Also forbidden are soups or gravies made from them. Salt and freshwater species of fish, amphibians, reptiles and shellfish are permitted, as are animal derived products such as margarine and gelatin which do not have any meat taste. On the Fridays outside of Lent the U.S. bishops conference obtained the permission of the Holy See for Catholics in the US to substitute a penitential, or even a charitable, practice of their own choosing. For most people the easiest practice to consistently fulfill will be the traditional one, to abstain from meat on all Fridays of the year. During Lent abstinence from meat on Fridays is obligatory in the United States as elsewhere.