Civil Service Personnel Rule 183
183. The preliminary enquiry shall not be made in the following cases:
(a) the case which is obvious that the complaint has no reasonable ground;
(b) the case which has regative contribution to the maintenance of disciplines by making the enquiry;
(c) the case in which the action or omission of the service personnel is just a minor case and the said service personnel admits his guilt;
(d) the case in which there is sufficient facts or evidence and so the departmental enquiry may be initiated from the stage of charge;
(e) the case which is obvious that the service personnel is responsible for any action or omission under the report of audit team and only the departmental enquiry is opened by treating the findings of the audit team as evidence to charge;
(f) the case in which the imposition of only disciplinary penalty is needed in the light of conviction according to criminal action.