In this work, we describe the main processes by which an agent operating in a normative/ethical system may formulate a new normative/ethical rule. This is an issue that emerges as fundamental in hybrid societies, where humans and autonomous agents shall live together. In these environments, it may occur a situation that is totally unknown to the agent, who may be unable to apply existing rule and need to create new ones to deal with the novelties encountered. We employ, as a means to devise the revision operators, the defeasible deontic logic (DDL), a non-monotonic logical system that accommodates rules of ethical origin, and has been widely employed for normative and moral reasoning. New rules may be acquired by an external source, possibly an institution, or a human interacting with an intelligent agent. The agent itself may learn it in a number of manners. We introduce two revision operators for norms that are able to manage the effects of all the above-mentioned processes.