My iffy entry:
The European Union - Confederation and Association
The exit of the United Kingdom from the then European Union had a cascade effect on inter-European politics. 75 years later there are now 2 parts to the European Integration Project - the core Confederate Members of the European Union and the peripheral Associate Members of the European Union.
The core Confederation, commonly called the European Union following the late US President Beavis's jokes about "the Confederacy", exists as a federal political union with a common currency, parliament, security force, etc.
The Associate Members are grouped in a series of Associations each having varying levels of integrated services with the EU core. These are the Atlantic Association, Mediterranean Association, Northern (or Baltic-Nordic) Association, and the Eastern Association.
The general EU flag remains but a new one created for each Association and the Confederation.
The EU Confederal Flag was inspired by the historical imperial flags of Europe, specifically France and the Holy Roman Empire, due to its resemblance to a larger Frankish Empire.
It is composed of a two headed eagle representative of the past and the future, each talon clutches a lightning bolt to symbolise the energy and zeal of the Project and the willingness to defend it. Upon the chest is a shield bearing the EU circle of stars. All is in EU colours of gold and blue.