(2)The year of allotment of an officer in service at the commencement of these rules shall be the same as has been assigned to him or may be assigned to him by the Central Government in accordance with the orders and instructions in force immediately before the commencement of these rules: (3)The year of allotment of an officer appointed to the Service after the commencement of these rules, shall be (a) where the officer is appointed to the Service on the results of a competitive examination, the year following the year in which such examination was held; (b) where the officer is appointed to the Service by promotion in accordance with rule 9 of the Recruitment Rules, the year of allotment of the junior most among the officers recruited to the Service in accordance with rule 7 of those Rules who officiated continuously in a senior post from a date earlier than the date of commencement of such officiation by the former: Provided that the year of allotment of an officer appointed to the Service in accordance with rule 9 of the Recruitment Rules who started officiating continuously in a senior post from a date earlier than the date on which any of the officers recruited to the Service, in accordance with rule 7 of those Rules, so started officiating shall be determined ad hoc by the Central Government in consultation with the State Government concerned; 116 Rule 4 relates to seniority of officers and reads as follows: "4.