I'm not sure. Devoir de réserve has to do with secrecy, self-restraint. When you're hired as a civil servant you have to submit to this devoir de réserve. It means you must watch what you say to outsiders.
reserve duty , I'm afraid, only relates to serving in the Army or something.
Yes, I understand that's what put you on that track.
But I don't think devoir de réserve has anything to do with being an army reservist.
You're submitted to that devoir whenever you work for the state. (as a soldier, a teacher, a postman, a judge... or anything).
I have no idea what the equivalent English expression could be. I just wanted to clear up the meaning of the French phrase.
I just mentioned the army as an example but actually it concerns a civil servant in the schooling system( I was insulted by a pupil, I had no support from my administration and I 'm considering about writting an article or at least a letter in a newspaper to expose the situation and put pressure on the headmaster and the administration...enough with my life (sorry)
I think the catchphrase is "professional discretion" .
High-level positions in government carry with them the obligation of professional discretion.
Professional discretion is requisite/obligatory/compulsory in high-level governmental positions.
Le devoir de réserve , ce n'est pas garder un secret, mais être discret:
devoir de réserve: Devoir de discrétion dans le comportement et les propos auxquels sont tenus les fonctionnaires, notamment pour ce qui concerne leurs opinions politiques et leurs activités professionnelles.