Are you obliged to register?
Yes, if you are a Swiss citizen, have taken up residence abroad, and are not registered with a Swiss municipality neither with another Swiss representation.
You have to register within 90 days after the announcement of departure to a foreign country and show a certificate of departure issued by the municipality of the last place of residence in Switzerland.
Registration will facilitate future administrative dealings with the Swiss representation responsible for your place of residence abroad, such as applications for Swiss passports and identity documents, transcription of a civil status event, registration for voting, etc.