JUDGMENT B.K. NAYAK, J. This writ application has been filed by the petitioners to quash appointment of opposite party Nos.6 to 25 to the post of Sikshya Sahayak under Annexure-13 and to direct the Collector, Puri to appoint the petitioners in the posts after quashing the order dated 28.10.2010 passed by the Collector in S.S. Misc. Case No.1 04 of 2009 under Annexure-14 whereby the claim of the petitioners for appointment was rejected. 2. The petitioners are all Scheduled caste persons, who applied for the post of Sikshya Sahayak in the district of Puri as per the advertisement (Annexure-1) issued by the Director, OPEPA, Orissa, Bhubaneswar-opposite party NO.3. Undisputedly for the district of Puri the number of posts of Sikshya Sahayak under the advertisement was 1109 with the breakup of unreserved-383, SEBC-299, S.C.-179 and S.T.-248. The petitioners were eligible and applied for the post, got selected having qualified but they could not get appointment because their position in the merit list for Scheduled Castes was below 179, i.e., the number of posts advertised for their category. However, it is apparent from Annexure-4, the letter of the Collector, Puri addressed to the Joint Secretary to Government, School and Mass Education Department that out of 248 seats reserved, for S.T. candidates, only ten posts were filled up by the candidates selected under that category and 238 number of posts remained vacant for want of qualified ST candidates. Therefore, by the letter dated 13.08.2007 under Annexure-4, the Collector requested the Government to de-reserve 238 S.T. posts for giving appointment to qualified candidates from other categories. Although initially vide letter dated 01.05.2008 under Annexure-6 the Government intimated the Collector refusing for de-reservation of the S.T. posts, however, by subsequent letter dated 03.07.2008 under Annexure-7 the request for de-reservation of 238 vacant S.T. posts was allowed. The said letter indicates that the Government decision allowing de-reservation was made in consultation with Department of S.T. and S.C. Development. It was stipulated that the appointment in de-reserved posts shall be purely on temporary basis with condition that as and when candidates of reserved category became available they may be inducted in the post. This Government decision is further reiterated in Government order dated 14.11.2008 under Annexure-11. On the basis of the Government order under Annexure-7, opposite party Nos.6 to 25, who are admittedly all general and SEBC candidates were appointed against the de-reserved vacancies. 3. This Government decision is further reiterated in Government order dated 14.11.2008 under Annexure-11. On the basis of the Government order under Annexure-7, opposite party Nos.6 to 25, who are admittedly all general and SEBC candidates were appointed against the de-reserved vacancies. 3. It is the submission of the learned counsel for the petitioners that as per Section 6 of the Orissa Reservation of Vacancies in Posts and Services (for Scheduled Castes and Scheduled Tribes) Act, 1975 (in short 'the ORV Act') the reserved vacancies for S.C. and S.T. shall at the first instance be exchanged between those categories in the event non-availability of qualified candidates from the respective communities, prior to considering the case of de-reservation of the said reserved posts' as provided under Section 7 of the Act, and that neither the Collector nor the Government having considered the said fact de-reserved the vacant ST posts and appointed the private opposite parties, who are general candidates and SEBC candidates, which is not permissible. Raising such grievance the petitioners earlier approached this Court in W.P.(C) No.14698 of 2010, which was disposed of on 27.09,2010 giving liberty to the petitioners to file representation before the Collector-cum-C.E.O., Puri for considering their case. Pursuant to the aforesaid order, the petitioners approached the Collector, Puri by filing representation which was registered as S.S. Misc. Case No. 104 of 2009 and by order dated 28.10.2010 (Annexure-14), the Collector rejected the said representation, mainly on the ground that the Supreme Court in the case of M. Nagraj and others has observed that incase of non-availability of particular class of candidates, the posts meant for them cannot be de-reserved to be filled up by other categories of candidates and, therefore, exchange of reservation between ST & SC will not be permissible. The operative portion of the order of the Collector in paragraph-7 of the order is as hereunder: "7. Government in SC & ST Development Department vide their letter No.11124 dated 15.3.2007 has communicated all Collectors the decision of the Hon'ble Supreme Court of India vide their judgment dated 9.10.2006 in the case of M. Nagraj and others, Hon'ble Supreme Court has observed in their order that in case of non-availability of a particular class of candidate the same cannot be de-reserved to be filled up by other categories of candidates. In other words exchange of reservation between ST and SC will not be permissible. In other words exchange of reservation between ST and SC will not be permissible. In view of the said orders of the Hon'ble Supreme Court filling up of ST backlog vacancies by SC candidates on exchanging cannot be done. Hence, the claim of the petitioners merits no consideration. Pronounced the order in the open Court on this day the 28th October, 2010. Intimate all concerned." In assailing the impugned order, the learned counsel for the petitioners submits that exchange of vacancies between, ST and SC as per Section 6 of the ORV Act is imperative and that question of de-reservation of any particular reserved category of SC or ST under Section 7 of the Act is not permissible before consideration of the question of exchange of posts between them in terms of Section 6 of the ORV Act. 4. Opposite party Nos. A and 5 have filed an affidavit stating inter alia that for want of qualified candidates, 235 numbers of posts meant for Scheduled Tribe candidates could not be filled up and, therefore, the State Government issued instruction to appoint the candidates belonging to other categories out of the select list on temporary basis and as such the authorities issued appointment letters in favour of the candidates empanelled in the merit list. It is further stated that the contention raised by the petitioners with regard to applicability of Section 6 of the O.R.V. Act has no force in view of the proviso to the said section. It is stated that appointment of Sikshya Sahayak is contractual, under a scheme with the condition that on completion of few years of service as Sikshya Sahayak the incumbent will be regularized against the post of Primary School Teacher, which carries a scale of pay and is a Class-III (Group-C) Post under the State Government. Therefore, Sikshya Sahayaks are Group (C) employees and because of the proviso to Section 6 of the O.R.V. Act, which is in the nature of an explanation, the main provision of Section 6 with regard to exchange of posts between SCs and STs has no application. It is further stated that the Government has published a resolution dated 10.01.2011 fixing different terms and conditions/guidelines for filling up the existing vacancies of Sikshya Sahayak and, therefore, the previous guidelines by virtue of which advertisement was issued in 2006, have no application. It is further stated that the Government has published a resolution dated 10.01.2011 fixing different terms and conditions/guidelines for filling up the existing vacancies of Sikshya Sahayak and, therefore, the previous guidelines by virtue of which advertisement was issued in 2006, have no application. It is also stated that the very question of exchange of post between SCs and STs relating to very same 2006 advertisement came up for consideration before this Court in W.P.(C) No.19146 of 2009 and a batch of connected writ applications and they were disposed of by a common order on 09.07.2010 by holding that exchange of vacancies in one reserve category by candidates of another reserved category or by candidates of general category shall not be applied to Class-III and Class-IV, employees. In view of such decision of this Court, the petitioners cannot claim appointment by way of exchange against vacant Scheduled Tribe posts. By virtue of a subsequent affidavit field by opposite party No.5 on 06.08,2012, it is stated that presently 74 numbers of vacancies for ST category are available. There is however no indication as to when and how the unfilled 235 posts meant for Scheduled Tribe were filled up. 5. The private opposite party Nos.6 to 25 have not filed any affidavit of their own. Learned counsel appearing for them only submits that since this Court has already decided the issue of exchange of posts of SCs and STs in W.P.(C) No.19146 of 2009 and the batch of connected writ applications and held that exchange is not permissible for the vacant posts of STs in question, that is binding on this Court and in the event this Court differs from the view expressed in the earlier decision, the matter may be referred to a larger Bench. 6. On the basis of the facts and contentions raised by the parties, the following questions fall for determination: (i) Whether de-reservation of vacant posts meant for Scheduled Tribe or Scheduled Castes under Section 7 of the O.R.V. Act is permissible ignoring the question of exchange of posts between SC and ST under Section 6 of the said Act wherever justified? (ii) ,'Whether the contractual posts of Sikshya Sahayak are covered, under the proviso to Section 6 of the O.R.V. Act and, therefore, exchange between SC and ST category of such posts is impermissible? (ii) ,'Whether the contractual posts of Sikshya Sahayak are covered, under the proviso to Section 6 of the O.R.V. Act and, therefore, exchange between SC and ST category of such posts is impermissible? (iii) Whether this Court is bound by the Single Bench decision rendered in W.P. (C) No.19146, of 2009 and the batch of writ applications and whether the matter is required to be referred to a larger Bench in case of disagreement with the view expressed therein ? 7. The 2006 advertisement for the appointment of Sikshya Sahayak under Annexure-1 issued as per the Government Resolution dated 31.5.2006 (Annexure-15) reveals that the appointments would be purely contractual with a fixed monthly remuneration of Rs.2,000/-. The advertisement also specifically provides for applicability of the O.R.V. Act to the recruitment. There is no dispute that the petitioners were eligible Scheduled Caste candidates, who applied for the post meant for them and became qualified and their names were found in the select list, but they could not get appointment as the posts meant for Scheduled Castes were completely filled up due to appointment of more meritorious selected SC candidates. Admittedly, 238 number of posts out of the total number reserved for ST candidates could not be filled up due to non-availability of qualified candidates of that category. The petitioners, therefore, claim that they being qualified SC candidates, they should have been appointed in the vacant posts meant for ST candidates by way of exchange as provided under Section 6 of the O.R.V. Act by the appointing authority, instead of the authority requesting the Government to de-reserve the vacant ST posts for the purpose of appointment of other categories of candidates, namely, General and SEBC and the Government should not have dereserved the said vacant ST posts before appointment of qualified SC candidates by way of exchange. It is apposite, at this stage, to see the relevant provisions of Sections 6 and 7 of the O.R.V. Act which are as follows: "6. It is apposite, at this stage, to see the relevant provisions of Sections 6 and 7 of the O.R.V. Act which are as follows: "6. Exchange of reservation between the Scheduled Castes and Scheduled Tribes- The reserved vacancies in appointments shall be exchanged between the Scheduled Castes and Scheduled Tribes in the event of non-availability of candidates from the respective communities but the vacancies reserved for a particular community shall continue to be reserved for that community only for two recruitment years and if candidates are not available for appointment in particular reserved vacancies in the third year, the vacancy so filled by exchange shall be treated as reserved for the candidates of that particular community who are actually appointed: [Provided that nothing in this Section shall apply to reserved vacancies in appointments in respect of Class III and Class IV posts and services.] 7. Carry-forward of reservation and de-reservation - If, in any recruitment year, the number of candidates either from Scheduled Castes or Scheduled Tribes is less than the number 'of vacancies reserved for them even after exchange of reservation between the Scheduled Castes and Scheduled Tribes, the remaining vacancies may be filled lip by general candidates after de-reserving the vacancies in the prescribed manner, but the vacancies so de-reserved may be carried forward to subsequent three years of recruitment: Provided ... It is the mandate of Section 6 of the O.R.V. Act that reserved vacancies shall be exchanged between STs and SCs in the event of non-availability of qualified candidates from the respective communities. Section 7 of the Act provides for de-reservation of vacancies meant for SCs or STs in case of non-availability of qualified candidates of those categories, but the Section specifically states that such de-reservation shall be done only after exchange of reservation between SCs and STs. It is, therefore, clear that provision of Section 6 takes precedence over Section 7 of the Act De-reservation under Section 7 is to be done in the manner prescribed in Rule 5 of the Orissa Reservation of Vacancies in Posts and Services (for Scheduled Castes and Scheduled Tribes) Rules, 1976 (In short 'the ORV Rules'). Under Rule-6 (1) (a) (vi) de-reservation of reserved vacancy shall be made by an appointing authority with the prior approval of the authority next above the appointing authority. Under Rule-6 (1) (a) (vi) de-reservation of reserved vacancy shall be made by an appointing authority with the prior approval of the authority next above the appointing authority. For exchange of reserved vacancies between SCs and STs no procedure has been prescribed, which otherwise means that it is the appointing authority, who has to exchange the reserved vacancies between the two categories in case of non-availability of qualified candidates of one category or the other. No approval from any higher authority is required for such exchange. Proviso to Section 6 of the O.R.V. Act has excepted the applicability of the main provision about exchange in respect of Class-III and Class-IV posts and services. In other words, no exchange of vacancies between SCs and STs is permissible in respect of Class-III (Group-C) and Class-IV (Group-D) posts. This means that exchange in the reserved vacancies of SCs and STs in respect of all other posts except Class-III and Class-IV is mandatory. 8. Now the question arises whether the posts of Sikshya Sahayak which are contractual posts with a fixed remuneration is a Class-III (Group C) or Class-IV (Group-D) post. Classification of different posts in services has been made in the Orissa Civil Services (Classification Control and Appeal) Rules, 1962 (in short 'CCA Rules, 1962'). Rule 6 of the CCA Rules provides for three classes of Civil Services of the State as Group-A, Group-B and Group-C. Rule .8 (1) provides that civil posts under the State other than those ordinarily held by persons to whom these rules do not apply or included in any State Civil Service, shall, by a general or special order of the Governor be classified as Group-A,' Group-B, Group-C and Group-D. Sub Rule (3) of Rule 8 provides that if any civil post under the State has not been classified by an order of the Governor and a question as to its classification arises, the decision thereon of the appropriate Department of Government after taking' into account the class to which another civil post carrying a comparable scale of pay belongs shall be final. 9. The learned Standing Counsel appearing for the School and Mass Education Department has not been able to show any order of the Governor about the classification of the service of Sikshya Sahayak. The post of Sikshya Sahayak does not admit of any scale of pay but a fixed remuneration. 9. The learned Standing Counsel appearing for the School and Mass Education Department has not been able to show any order of the Governor about the classification of the service of Sikshya Sahayak. The post of Sikshya Sahayak does not admit of any scale of pay but a fixed remuneration. Learned Standing Counsel has taken a stand that after few years of rendering service as Sikshya Sahayak a person can be regularized in the post of a Primary School teacher which carries a scale of pay. The contention is meaningless. Merely because a Sikshya Sahayak can be considered after some length of service for being observed against a Primary School Teacher post, that by itself cannot equate him with a Primary School Teacher. Therefore, it must be held that the post of Sikshya Sahayak which neither carries a scale of pay, nor in respect of which any order of the Governor has been issued grouping it in any class of services, it cannot be said to be a Class-III (Group-C) or Class-IV (Group-D) post. Evidently, therefore, proviso to Section 6 of the O.R.V. Act will have no application. Since the O.R.V. Act has been specifically made applicable to the recruitment of Sikshya Sahayak, exchange of vacancies between the reserved categories of SCs and STs should have been done by the authorities before consideration of the question of de-reservation of Scheduled Tribe vacancies. De-reservation made by the Government of the vacancies meant for Scheduled Tribe in the instant case therefore is illegal. The qualified selected candidates of Scheduled Caste category including the petitioners should have been considered for appointment against the vacancies meant for Scheduled Tribe by way of exchange. Question Nos.(i) and (ii) are answered accordingly. 10. Coming to question No.(iii), it is seen that W.P.(C) No.19146 of 2009 and the batch of the connected writ applications were disposed of by the learned Single Judge by a common order dated 09.07.2010 vide Annexure-B/5. The order reveals that the writ petitioners therein were S.C. candidates, who applied for appointment as Sikshya Sahayak pursuant to 2006 advertisement under Annexure-1. But, though they were found qualified, they were placed in the waiting list. They, therefore, filed the writ applications claiming appointment against the unfilled vacancies - meant for Scheduled Tribe communities. The order reveals that the writ petitioners therein were S.C. candidates, who applied for appointment as Sikshya Sahayak pursuant to 2006 advertisement under Annexure-1. But, though they were found qualified, they were placed in the waiting list. They, therefore, filed the writ applications claiming appointment against the unfilled vacancies - meant for Scheduled Tribe communities. While deciding the issue the learned Single Judge took into consideration, the guidelines for selection of Sikshya Sahayak issued by the Government in School and Mass, Education Department vide resolution dated 31.5.2010, though, in fact, the advertisement of 2006 was never issued, in pursuance of the said resolution, but it was issued pursuant to government Resolution dated 31.5.2006 (Annexure 5 to the rejoinder affidavit filed by the present• petitioner) of which Clause-4.2 clearly stipulated that against SC and ST quota non-SC/ST candidates shall not be engaged. Paragraph-5 of the order of the learned Single Judge in the batch of writ petitions reveals that the petitioners therein placed reliance on Section 6 of the O.R.V, Act. After quoting the provision of Sections 6 and? of the O.R.V. Act, in paragraph-6 of the order, the learned Judge observed as under: "6. Thus, a bare reading of these provisions reveals that the exchange i.e., filling up the unfilled vacancies in one reserved category by candidates of another reserved category by candidates of another reserved category or by candidates of general category shall not be applied in Class-III and Class-IV employees. So, contention that the ST candidates in view of insufficient number of candidates eligible should be filled up by S.C. candidates is of no avail." Ultimately, considering the fact that in W.P.(C) No.3762 of 2009 this Court directed the Collector, Puri to reconsider the case of the petitioner therein, namely, Biswanath Behera, the learned Judge in paragraph-7 of the order directed all the writ petitioners to file fresh representation before the Collector, Puri, who should examine and find if the petitioners were eligible to be appointed. But the fact remains that in paragraph-6 of the order, as quoted above, the learned single Judge concluded that the writ petitioners, who were Scheduled Caste candidates were not eligible to be appointed against the unfilled vacancies meant for Scheduled Tribe in view of the proviso to Section 6 of the O.R.V. Act. But the fact remains that in paragraph-6 of the order, as quoted above, the learned single Judge concluded that the writ petitioners, who were Scheduled Caste candidates were not eligible to be appointed against the unfilled vacancies meant for Scheduled Tribe in view of the proviso to Section 6 of the O.R.V. Act. However, no finding has been recorded as to whether the post of Sikshya Sahayak comes within Class-III or Class-IV posts, far less any reason assigned for the conclusion. 11. Though my finding recorded above that the post of Sikshya Sahayak does not come within the purview of Class-III (Group-C) or Class-IV (Group-D) service is in disagreement with the earlier view expressed by the learned Single Judge in the aforesaid batch of connected writ applications, it is not necessary to follow the said decision because it was sans reasons and without reference to statutory rules and other provision of law and, theref0re, it has no binding force. Law in this regard, as can be seen below, is quite clear and the matter needs no reference to larger' Bench. 12. It has been held by the apex Court in the case of State of U.P. and another v. Synthetics and Chemicals Ltd and another; (1991) 4 SCC 139 as under: "39. But the problem has arisen due to the conclusion in the case of Synthetic and Chemicals. The question was if the State legislature could levy vend fee or excise duty on industrial alcohol. The Bench answered the question in the negative as industrial alcohol being unfit for human consumption the State legislation was incompetent to levy any duty of excise either under Entry 51.or Entry 8 of List II of the Seventh Schedule. While doing so the bench recorded the conclusion extracted earlier. It was not preceded by any discussion. No reason or rationale could be found in the order. This gives rise to an important question if the conclusion is law declared under Article 141 of the Constitution or it is per incuriam and is liable to be ignored. 40. 'Incuria' literally means 'carelessness'. In practice per incuriam appears to mean per ignoratium. English Courts have developed this principle in relaxation of the rule of stare decisis. The 'quotable in law' is avoided and ignored if it is rendered, 'in ignoratium of a statute or other binding authority'. (Young v. Bristol Aeroplane Co. Ltd.). 40. 'Incuria' literally means 'carelessness'. In practice per incuriam appears to mean per ignoratium. English Courts have developed this principle in relaxation of the rule of stare decisis. The 'quotable in law' is avoided and ignored if it is rendered, 'in ignoratium of a statute or other binding authority'. (Young v. Bristol Aeroplane Co. Ltd.). Same has been accepted, 'approved and 'adopted by this Court while interpreting Article 141 of the Constitution which embodies the doctrine of precedents as a matter of law. In Jaisri Sahu v. Rajdewan Dubey this Court while pointing out the procedure to be followed when conflicting decisions are placed before a bench extracted a passage from Halsbury's laws of England incorporating one of the exceptions when the decision of an appellate Court is not binding. 41. Does this principle extend and apply to a conclusion of law, which was neither raised nor preceded by any consideration. In other words can such conclusions be considered as declaration of law? Here again the English Courts and jurists have carved out an exception to the rule of precedents. It has been explained as rule of sub-silentio. "A decision passes' sub-silentio, in the technical sense that has come to be attached to that phrase, when the particular point of law involved in the decision is not perceived by the Court or present to its mind." (Salmond on Jurisprudence 12th Edn., P.153). In Lancaster Motor Company (London) Ltd. y. Bremith Ltd. The Court did not feel bound by earlier decision as it was rendered 'without any argument, without reference to the crucial words of the rule and without any citation of the authority' it was approved by this Court in Municipal Corporation of Delhi v. Gurnam Kaur. The bench held that 'precedent sub-silentio and without argument are of no moment'. The Courts thus have taken recourse to this principle of relieving from injustice perpetrated by unjust precedents. A decision which is not express and is not founded on reasons nor it proceeds on consideration of issue cannot be deemed to be a law declared to have a binding effect as is contemplated by Article 141. Uniformity and consistency are core of Judicial discipline. But that which escapes in the judgment without any occasion is not ratio decidendi. A decision which is not express and is not founded on reasons nor it proceeds on consideration of issue cannot be deemed to be a law declared to have a binding effect as is contemplated by Article 141. Uniformity and consistency are core of Judicial discipline. But that which escapes in the judgment without any occasion is not ratio decidendi. In B. Sharma Rao v. Union Territory of Pondicherry it was observed, 'it is trite to say that a decision is binding not because of its conclusions but in regard to its ratio and the principles laid down therein'. Any declaration or conclusion arrived without application of mind or preceded without any reason cannot be deemed to be declaration of law or authority of a general nature binding as a precedent. Restraint in dissenting or overruling is for sake of stability and uniformity but rigidity beyond reasonable limits is inimical to the growth of law." Similar view has also been expressed in AIR 1989 SC 38 ; Municipal Corporation of Delhi v. Gurnam Kaur, AIR 2006 SC 2449 ; Mayuram Subramanian Srinivasan v. C.B.I. and AIR 2012 SC 1485 ; Rattiram and others v. State of M.P. through Inspector of Police. 13. The petitioners and other Scheduled Caste candidates as per the select list of 2006 are entitled to be appointed against the unfilled vacancies meant for Scheduled tribe community in accordance with their merit in the select list. The contention of the learned State counsel that in the meantime new guidelines have been issued in 2011 for filling up vacancies in the posts of Sikshya Sahayak has no force in as much as the posts advertised in 2006 are to be filled up as per 2006 guidelines (Resolution) and by applying the O.R.V. Act and for that matter Section 6 thereof, and thereafter any left out vacancies or future vacancies shall be filled in accordance with the 2011 guidelines or any other new guidelines. 14. In the light of the discussions made above, the order of the Collector under Annexure-14 rejecting the claim of the petitioners is quashed so also the appointment of opposite party Nos.6 to 25 under Annexure-13. It is directed that the left out selected Scheduled Caste candidates from the select list of 2006 including the petitioners shall be appointed in accordance with their merit against unfilled vacancies meant for Scheduled Tribes by way of exchange. It is directed that the left out selected Scheduled Caste candidates from the select list of 2006 including the petitioners shall be appointed in accordance with their merit against unfilled vacancies meant for Scheduled Tribes by way of exchange. If after appointment of left out selected SC candidates, still vacancies meant for Scheduled Tribes become available, then the appointment of opposite party Nos.6 to 25, which has been admittedly made against ST posts, shall not be disturbed. The writ application is accordingly allowed. No costs. Application allowed.