Apologies for the delay in answering this. We are still working the bugs out of the system and were running a test.
Regarding the norms for fast and abstinence, the Code of Canon Law (1253) makes this provision for the national bishops’ conferences: “The Episcopal Conference can determine more particular ways in which fasting and abstinence are to be observed. In place of abstinence or fasting it can substitute, in whole or in part, other forms of penance, especially works of charity and exercises of piety” (emphasis added).
Accordingly, in 1966, the National Conference of Catholic Bishops (NCCB) decided: "Friday should be in each week something of what Lent is in the entire year. For this reason we urge all to prepare for that weekly Easter that comes with each Sunday be freely making of every Friday a day of self-denial and mortification in prayerful remembrance of the passion of Jesus Christ;
“Among the works of voluntary self-denial and personal penance which we especially commend to our people for the future observance of Friday, EVEN THOUGH WE HEREBY TERMINATE THE TRADITIONAL LAW OF ABSTINENCE AS BINDING UNDER PAIN OF SIN, as the sole prescribed means of observing Friday, we give first place to abstinence from flesh meat. We do so in the hope that the Catholic community will ordinarily continue to abstain from meat by free choice as formerly we did in obedience to Church law” (2-3; emphasis in original).
You can read the NCCB’s decision in context here: