When you do regulatory monitoring (especially in aviation), you see titles that look similar:
In practice, these three types of texts do not have the same role, the same adoption path, or the same consequences for compliance. Here is a clear explanation, with the EU “framework” references.
A delegated act is a non-legislative act that the legislator (Parliament + Council) authorises the Commission to adopt in order to supplement or amend certain non-essential elements of a legislative act.
The logic is: “we set the policy in the basic regulation/directive, and we delegate the technical details that evolve.”
An implementing act is used to set uniform conditions for implementing a legally binding act, when that is necessary.
The idea is simple: the EU adopts a rule, and to avoid 27 different (or incompatible) implementations, an implementing act is used to standardise certain parameters, formats, procedures, lists, templates, and so on.
A corrigendum is published to correct errors in an already published act (typos, reference errors, layout issues, sometimes translation errors), when the error creates doubt about the author’s intent.
Useful point: the Commission also distinguishes “correcting acts” when the error affects the substance of the act, versus corrigenda for error corrections (and these corrections are published in the Official Journal).
