I quote from TA (sic) regulations (which are available on
ArmyNet):
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3.082. Discipline and Service Law. Discipline is a fundamental requirement of effective Armed Forces. Service Law is an additional body of law that applies to the Armed Services which is contained in the 2006 Act and extant provisions in earlier Armed Forces Acts. Every member of the TA must be aware when they are subject to Service Law which is, as set out in Section 367 of the 2006 Act, when they are:
a. In Permanent Service, i.e. mobilized.
b. In Full Time Reserve Service (FTRS).
c. Undertaking Additional Duty Commitment (ADC).
d. On Training and Other Duties.
e. Serving as Permanent Staff, i.e. NRPS.
The 1980 and 1996 Acts are not Service Law, and apply at all times to all reservists. Indiscipline has no place in the
Army and is to be addressed by either formal disciplinary action or administrative action under AGAI 67.
3.083. Disciplinary and Administrative Action. The distinction between disciplinary and administrative action is
important. As a general rule, disciplinary action should be used where there is evidence that an offence has been
committed, where the application of Service Law is appropriate, and where an individual should, if convicted, be
punished. Minor administrative action is intended to correct professional and personal shortcomings. It should not be used as a substitute for disciplinary action. When minor administrative action is taken, the sanction should fit the
professional failing and be clearly designed to correct it, not to punish the individual. Major administrative action,
which includes discharge from the Service, may be taken in conjunction with, or following, disciplinary action.
Whilst
TA personnel and officers of the Cadet Forces are not subject to Service Law at all times, they are subject to Army
Values and Standards and Administrative Action at all times.
3.084. Explanation to Soldiers. The disciplinary provisions of the 1996 and 2006 Acts are to be explained to soldiers and officers during initial training. Any TA personnel suspected of committing an offence are to be made aware of their legal rights as explained in Annex G to Chapter 6 of the Manual of Service Law (MSL) “Your rights if you are accused of an offence under the Service justice system”.
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This would appear to be different from my understanding which was that officers were 'on duty' at all times and ORs when signed in or when under arms (carrying fire arms or ammo). This would appear to say that its the same for officers and soldiers and its when "On Training and Other Duties" with no requirement to sign in / out.
I will do a bit of digging because its not something I've been informed of.