|Alas, minor orders no more...|
1) when your confessor gives you absolution, you must obey;
2) if your local diocese or the council of bishops in your country declares a holy day of obligation or rules of abstinence and fasting particular to your diocese and/or country, you must obey.
3) of course, if your bishop asks all teachers in the Catholic schools to take the oath and promise of fidelity, you must obey, as that was a directive from Rome which the bishops can enforce;
4) if a bishop demands that all women who have been excommunicated for abortion, or anyone aiding or abetting an abortion needs to see him personally for the lifting of that, one must obey.
There are most likely more, but these were added by a smart seminarian who reads my blog.