Hansaria, J.:- Much water has flown after the petitioner approached this Court in December, 1980. His grievance then was relating to his supersession by respondents 1 to 9, who had been appointed to some posts in Grade-IV of Class-I of the Veterinary Service to which all of them belong. Even here, the grievance was originally confined to respondents 2 and 3 when the petitioner had approached the learned Assam Administrative Tribunal. Sub­sequently, other respondents also came to be so appointed. During the pendency of this Rule, the petitioner himself came to occupy such a post; and as such initial grievance no longer exists. But then, as the aforesaid promotions were based on draft gradation list prepared in September, 1977, the infirmity in that list, if any, did subsist for examination when the Rule was issued. The final gradation list having taken place of the draft gradation list, we are not called upon at this stage to examine the inter se positions of the parties in the draft gradation list. Shri J. P. Bhattacharjee, learned counsel for the petitioner, has, therefore, put forward the grievance of the petitioner qua the final grada­tion list issued on 17.9.80, but which had come to light much later. Another event took place about a month back, and the same relates to the regularisation of some of the respondents. It may be pointed out at this stage that most of the respon­dents had found their berth in Class-I of the service with the aid of Regulation 4 (d) of the Assam Public Service Commission (Limitations of Function) Regulations, 1951, hereinafter the Regu­lation. We shall have occasion to refer to the provision of this Regulation later. 2. Though Shri Bhuyan for the private respondents and Shri Das for the State urged that we may not go into the merits of the case in view of these developments which have rendered the petition as filed infructuous. They prayed that the petitioner may first be allowed to ventilate his grievance before the learned Assam Administrative Tribunal. We have, however, not thought it fit to concede to this prayer. According to us service matters should be dealt with promptly and the parties should not be allowed to fight different bouts of litigation at different levels. To do complete justice between the parties we have taken note of all the subsequent developments brought to our notice. 3. We have, however, not thought it fit to concede to this prayer. According to us service matters should be dealt with promptly and the parties should not be allowed to fight different bouts of litigation at different levels. To do complete justice between the parties we have taken note of all the subsequent developments brought to our notice. 3. Before we reach the heart of the matter, we have to uncover some layers. The first is relating to the very appointment of almost all the private respondents with the aid of aforesaid Regulation 4(d). Strictly speaking, we are not called upon to examine this aspect as the validity of their appointment orders has not been challenged. A writ quo-warranto cannot be issued in a collateral proceeding. Even so, we may note the submission made which has in fact lost its force in view of the subsequent regularisation. The point, however, made out by Shri Bhattacharjee is that recourse to Regulation 4(d) is permissible when officiating promotion is not likely to last for more than one year, as is stated in the provision itself. It is brought to our notice that the very appointment orders in favour of these respondents had themselves stated that the vacancies are "for a period of more than one year" and as such, according to the learned Counsel, recourse to Regulation 4(d) could not have been taken. In this connection our attention is invited to the proviso also. We may read this proviso along with Regulation 4(d) :- "4. Promtion.-It shall not be necessary to consult the Commission on the principles to be followed in making promotions or on the suitability of candidates for promo­tion in the following cases.- (a) * * (b) * * (c) * * (d) Officiating promotion for a period which is not likely to last for more than one year ; Provided that if the period of officiating promotion is extended beyond the term for which it was originally sanctioned, the period of promotion shall, for purpose of this regulation, be reckoned from the date when the pro­motion originally took effect and not from the date of the extension of the period". [emphasis supplied] According to Shri Bhattacharjee, the regulation-makers had known that even Regulation 4 (d) promotions may be extended from time to time, but the immunity from consulting the Public Service Commission was sought to be rigorously confined to a period which despite extensions was not likely to last for more than one year. The irregularity in promoting the respondents with the aid of Regulation 4 (d) does not, however, survive by now for our examination in view of the regularisation, the last order relating to which was passed on 18.5.83. We shall only refer to one decision of the apex Court in this regard. The same is that of B. N. Nagarajan vs. State of Karnataka, AIR 1979 SC 1676 . It has been pointed out in paragraph 5 of this judgment that the term "regularisation" is calculated to condone any proce­dural irregularities and is meant to cure such defects as are attributable to the methodology followed in making the appointments. (A similar view had also been expressed in S. T Venkataiah vs. State ATR 1969 Mysore 186). So, we may not detain ourselves with his aspect and may travel towards the core of the matter. 4. Another hurdle put which has to be cleared to travel as aforesaid lies in a terminological tangles. This is about the nature of the promotion of the respondents. Reference to the relevant orders, which are at Annexures IV to VI, would show that they were promoted "temporarily" and were "appointed to officiate" in the posts in question. Shri Bhattacharjee has characterised these appointments as adhoc in nature. According to Shri Bhuyan we have, however, to make a distinction between adhoc appoint­ments and officiating appointments. According to the learned counsel an appointment can be said to be "adhoc" only when the same is foe a particular purpose. This was not the case here, contends Shri Bhuyan. In this connection, we may refer to a Full Bench decision of the Punjab & Harayana High Court in S. K. Verma vs. State, 1979 SLJ 477. In that case, the dictionary meaning of the term "adhoc" as given in Webster's New International Dictionary and in Randam House Dictionary had been noted. As per these, the term 'adhoc' means "partaining to or for the sake of this case alone"; or for this special purpose, with respect to this subject or thing. In that case, the dictionary meaning of the term "adhoc" as given in Webster's New International Dictionary and in Randam House Dictionary had been noted. As per these, the term 'adhoc' means "partaining to or for the sake of this case alone"; or for this special purpose, with respect to this subject or thing. It was, therefore, stated that in the gamut of service law, an adhoc employee virtually stands at the lowerstrung implying that such an employee had been engaged casually, or for a short duration or fleeting purposes. 5. Shri Bhattacharjee has drawn our attention to certain observations made in some Supreme Court decisions where officiating hand was also described to have no better right. In Union of India vs. K. R. Tahiliani, AIR 1980 SC 953 , it was stated that an officiating hand has no right to the post and is perhaps a fleeting bird. As in the case at hand, we are really not concerned with the right of the officiating appointees to hold the post, but whether the period of officiation could be counted for the purpose of seniority, we do not propose to pursue this aspect of the matter. 6. Before addressing ourselves on the substantial question posed before us, we may state that the cases at hand do not seem to be governed by any service rules or executive instructions, though some reference has been made to some instruction finding place in the "Handbook of General Circulars" issued by the Government of Assam. The one that is pressed most in service is paragraph 7. 1 finding place in Chapter-II which deals with "General Conditions of Service". That paragraph reads :- "7. 1. If all the officers are promoted from a junior service their respective seniority in the former service is to be retained and when the same batch consists of both promoted officers and direct recruits, the former are to gain seniority over the latter." According to us, this Rule would be attracted if all the Officers: were to be promoted on one and the same date. If, however, the dates of promotions be different, it would be difficult to hold that even in such a case the seniority is to be determined with reference to the ranking in the junior cadre. If, however, the dates of promotions be different, it would be difficult to hold that even in such a case the seniority is to be determined with reference to the ranking in the junior cadre. Instruction No. 10 finding place in this Chapter has also no application because the one which is relevant, namely, 10.2, deals with appoint­ments which were first made under Regulations 3(e) or (f) of the aforesaid Regulations and later regularised through the public service Commission. In the instant case, we are concerned not with the appointment under Regulation 3(e) or 3(f), but with pro­motion with the aid of Regulation 4(d). Let it also be said that the proviso to Regulation 4(d), mentioned by Shri Bhuyan in this context, has no application to determine the question of seniority and cannot assist the respondents, as the date of first promotion has to be reckoned, not for any other purpose, but for the purpose of the Regulation, which does not deal with the question of seniority. 7. The all important question, therefore, is if there be no rules or instructions holding the field, can Continuous officiating in a post be taken into consideration for determining seniority ? According to Shri Bhattacharjee, it is regularisation alone which is material as officiating appointments do not give rise to any legal right. Strong reliance is placed in this connection on Satyabrata vs. State of Assam, AIR 1975 SC 487. That was a case where the Court was seized with the question of determination of inter se seniority of the persons who had been first appointed under Regulation 3 (e), and were thereaftes regularised. Instruc­tion, No. 10. 2, therefore, governed their cases which had stated, inter alia, that if the appointments of a number of persons are regularised in one batch, then the inter se seniority of these persons should be according to the merit list. It may be stated that the regularisation in that case of all the persons had been recommended in one batch by indicating their merit order. As the appellants hid, however, been appointed under Regula­tion 3 (e) earlier to the respondents, they claimed seniority over the latter which was rejected, by observing that their app­ointments under Regulation were defeasible and could not give rise to any legal right. The view taken by this Court on the basis of the aforesaid Instruction 10. 2 was, therefore, upheld. 8. The view taken by this Court on the basis of the aforesaid Instruction 10. 2 was, therefore, upheld. 8. This decision is distinguishable on many counts. First the matter was governed by executive instructions which field the field in the absence of service rules. As already pointed out there is no such instruction to govern the present cases. Secondly, and what is more important, the Court had not gone into the question whether officiating period could be counted for the purpose of seniority in the absence of any rules or executive instructions. Finally, in view of later decisions of the apex Court, it does not seem correct to state that officiating appointment could not confer any legal right for any purpose. 9. Let us see what these later decisions are. At first, we may refer to N. K. Chauhan vs. State of Gujarat, AIR 1977 SC 251 wherein it was observed in para 40(c) after -'brief and quick survey of decided cases": "Seniority, normally, is measured by the length of continuous officiating service-the actual is easily acceptable as the legal. This does not preclude a different prescrip­tion, constitutionality tests being satisfied". What has been stated in S. B. Patwardhan vs. State of Maharashtra AIR 1977 SC 2051 , is more revealing, in that case, the validity of the rule as per which seniority was to be determined with reference to the date of confirmation came to be tested. The rule was struck down being violative of Articles 14 and 16 of the Constitution by pointing out that the rule left the valuable right of seniority to depend upon the mere accident of confirmation. It was pointed out that the result of following the rule would be that a direct recruit appointed on probation, say in 1966, was to be regarded as senior to a promotee, who was appointed to the same post in an officiating capacity, say in 1956, but was confirmed in 1966. The confir­mation was regarded as one of the "inglorious uacertainties of Government service depending neither on efficiency of the incum­bent nor on the availability of substantive vacancies, (see para 39). In this connection, reference was made to a widely known case where a distinguished member of the judiciary was confirmed as a District Judge years after he was made a Judge of the High Court. In this connection, reference was made to a widely known case where a distinguished member of the judiciary was confirmed as a District Judge years after he was made a Judge of the High Court. Much of what has been stated about confirmation would apply to regularisation. We can bring home this aspect by referring to the dates of regularisation of the services of the incumbents at hand when they were holding posts in Class-II. In the case of the petitioner, his regularisation came within 17 days. But in the case of respondent No. 8 it took 15 years, and 13 years in cases of respondents 2 and 7. So, the date of regularisation cannot be taken to be a sound yardstick to deter­mine seniority. Indeed, if it were to be so done it could be violative of Articles 14 and 16 of the Constitution. 10. Before noting the ratio of Baleshwar Dass AIR 1981 SC 111 we may with profit refer Rajendra Narain vs. State of Bihar, AIR 1980 SC 1246 , in which determination of seniority on the basis of continuous officiation was held to be valid. It has been held in Ram Krishna Tiwari vs. High Court of Madhya Pradesh, 1981 (2) SLR 47 that in the absence of rules seniority has to be reckoned from the date of officiation. 11. Baleshwar Dass has not left anything to doubt in this connection. Though in that case, seniority has to be determined according to the date of the appointment order, and for one to be a member of the service, the appointment must have been in a substantive capacity, and the main question examined was whether a person appointed to a temporary post could also be said to be holding a post in a substantive capacity, the aspect with which we are concerned had also been flashed at many places. In paragraph 29, it was stated that for the purpose of counting seniority the appointment need not necessarily be to a permanent post it would be sufficient even if appointment is to a temporary post of long duration. Reference was then made to Patwardhan and Chauhan's cases and it was held that these decisions have clarified "the equal value of officiating service". Para 34 states that once the incumbents are held to be occu­pying the posts in substantive capacity "the entire officiating service can be considered for seniority". Reference was then made to Patwardhan and Chauhan's cases and it was held that these decisions have clarified "the equal value of officiating service". Para 34 states that once the incumbents are held to be occu­pying the posts in substantive capacity "the entire officiating service can be considered for seniority". It had earlier been stated in para 20 that "we must also express emphatically that the principle which had received the sanction of this Court's prono­uncements is that officiating service in a post is for all prac­tical purposes of seniority as good as service on a regular basis", though it was admitted that the regular service alone could be counted for seniority provided the rules in that regard are clear and categoric and do not admit of any ambiguity and "cruelly arbitrary cut-off long years of service" or "there is func­tionally and qualitatively substantial difference in the service rende­red in the two types of posts". 12. These pronouncements do not leave room for any hesi­tation on our part to hold that the continuous officiation in the present cases had to be reckoned in the absence of any rule to the contrary for determining inter se seniority of the incum­bents before us. If it is so done, there is no denial that res­pondents 1 to 5 and 7 to 9 would be senior to the petitioner. Respondent No. 6 having found his place in Class-1 on 6.3.77, has been shown in both the draft gradation list as junior to the petitioner. This is not all. The services of respondents I to 5 and 9 have been regularised on 18.5.83, though their initial appo­intment was on 10.6.76. The effect of regularisation is, as per the learned Government Advocate, that the date of regular appo­intment itself must be deemed to relate back to the date of officiating promotion. In this connection, reference is made to Kuldeep Chand vs. Delhi Administration, 1978 (2) SLR 379. In that case, a Division Bench of the Delhi High Court had taken the aforesaid view. Shri Bhattacharjee contests this position by drawing out attention to the order of regularisation itself which is at Annexure-X of the additional affidavit-in-opposation filed on behalf of respondents 1 to 7. It is contended that notification has only stated that the appointments of the concerned persons "are hereby regularised without prejudice to the claims of seniority and promotion of other officers". It is contended that notification has only stated that the appointments of the concerned persons "are hereby regularised without prejudice to the claims of seniority and promotion of other officers". As against this, the regularisation order at Annexure-Z has stated that the appoint­ments of persons mentioned in the notification are "hereby regularised with effect from the date of their appointment/joining to the posts". It is, therefore, contended that the notifica­tion at Annexure-Z having clearly stated that the regularisation was with effect from the date of appointments/joining, and this being missing in the notification at Annexure-X, we may not read that these regularisation related back to the date of appoint­ment. It seems to us that this would be only taking advan­tage of the wordings of the two notifications which are six years removed from each other. Though in Annexure-X it is not stated that the regularisation is with effect from the date of appoint­ment, number and date of notifications under which the appoint­ments had been made are quoted. This apart, what was being regularised was the appointments. It would thus seem to us that the regularisation has to relate back in these cases as well to the date of appointment. May we make it clear that on the legal aspect of relating back their above is our tentative view only. 23, ID any case, the period of continuous officiation could not have been excluded while determining the inter se seniority for reasons given above. We would, therefore, hold that the grieva­nce of the petitioner is not well-founded. Accordingly, the peti­tion is dismissed and the Rule is discharged. We may, however state before parting that the determination of seniority of resp­ondents 1 to 4 as Deputy Director (Class-1) in the final grada­tion list does not seem to be regular, as their appointments to these posts have not yet been even regularised.