Should a Catholic hospital or Catholic university cafeteria sell meat dishes on Fridays during Lent? Wouldn’t this be material cooperation with sinful acts?
Such cafeterias serve a wider public than Catholics alone, and it is perfectly fine for those non-Catholics to eat meat on Lenten Fridays. So it would not be wrong for Catholic cafeterias to sell meat dishes on Lenten Fridays. But it would be a courtesy to the Catholic patrons for the management to post a sign reminding Catholics that this is a Lenten Friday and therefore Catholics are required to abstain from meat.