Rabbinic enactments are all supported by the biblical law of "Lo tasur," forbidding straying from after their words: Berachot 19b
One who changes any element of the Rabbinically instituted format of a Bill of Divorce: Gittin 5b
Collecting Ketubah Money given to Wife on Widowing or Divorce from the poorest quality of grain: Ketuvot 10a
An edict overturning the standard rule requiring that a claimant must prove his right to the money he claims: Ketuvot 27b
Refusing an enactment which was established for one's benefit: Bava Kama 8b
Refusing an enactment because it does not help: Bava Metzia 49b
From the time when the Rabbinic Prohibition sets in, the Leaven no longer belongs to its owner, except for liability for the prohibition against owning the Leaven: Pesachim 6b-7a, 21b
One is not considered to be the owner of a pit dug in public property, except under the Rabbinic designation for liability: Pesachim 6b-7a
Creating an Edict which will require extraordinary expenditure of money or physical effort: Pesachim 10b
The Courts' Power over Standing Edicts/Institutions
Changing an Institution because of danger from the Monarch: Ketuvot 3b
Power of the Rabbis to believe someone on a Rabbinic issue, to annul the Money which they designated for a Widowed/Divorced Woman: Ketuvot 10a
Power of the Rabbis to believe someone on a Rabbinic issue, to believe anyone who says they Searched for Leaven: Pesachim 4b
References to Later Edicts/Institutions in the Torah
The Amount of money paid to a Widow upon being widowed/divorced from her [2nd] marriage: Ketuvot 10b
