P. Subramonian Poti, Ag. C.J.
1. The main question arising for decision in this revision is whether sewing thread is cotton yarn. During the relevant period cotton yarn was taxable only at the point of first sale in the State by a dealer who is liable to tax under Section 6. We are concerned in this tax revision case with an assessment order of the year 1973-74 during which year the revision petitioner-firm was carrying on the business of sale of sewing machines, cotton thread, etc. The firm was assessed to sales tax on the turnover of sewing thread, silk yarn, lace cloth and woven lace. It is the taxation of these items that is under dispute in this revision. The assessing authority, the Appellate Commissioner and the Tribunal have all held that the sales of these items are liable to tax. That is challenged in this revision.
2. As indicated earlier sewing thread was contended to be cotton yarn so much so that according to the assessee he is not liable to tax on the sales of sewing thread as the sale was at the second point in the State and not the first and the sale at the first point had been taxed. If the item which was sold is not shown to be cotton yarn naturally it will be liable to tax at every point of sale and, therefore, the sales tax authorities would be right in assessing tax on the turnover of sewing ttiread. Item 4(ii) in the Second Schedule of the General Sales Tax Act is 'cotton yarn, other than handspun yarn, but not including cotton yarn waste'. The rate of tax at the point of first sale in the year 1972-73 was 1 per cent and the general rate of tax during that year was 3 per cent. Cotton yarn, according to the revision petitioner, includes not only spun yarn as such but also yarn converted into thread or into other forms, for, according to the petitioner, the goods even then essentially retain their character as cotton yarn and therefore would fall within item 4(ii) of the Second Schedule.
3. Cotton yarn is no doubt used for the purpose of manufacturing sewing thread. Sewing thread is sold for purposes different from that for which cotton yarn is sold. Cotton yarn is consumed for the manufacture of textiles but sewing thread is not one of the components in the manufacture of textiles.
4. In understanding the provisions of the Sales Tax Act and particularly the entries which relate to specific items of goods, so long as there is no definition in the statute itself, courts are guided by the meaning of the terms as understood in common parlance. People associated with the trade or business concerning the commodity would understand the term in a particular sense and it is that sense which should apply. It may be that by some process goods of one category are changed into another but still they may retain their identity. Normally two tests are applied to ascertain whether goods known by two different names really belong to one and the same category. Two tests normally formulated are: (1) Do the goods retain their identity notwithstanding the change (2) Are the goods accepted commercially as the same despite the change ?
5. For the manufacture of sewing thread no doubt cotton yarn is used. By a process of spinning a number of yarns together the sewing thread is manufactured. But in this process the cotton yarn loses its identity. It would no longer be cotton yarn. It is not possible, commercially, to reconstitute the sewing thread into cotton yarn.
6. Sewing thread is commercially a product different from cotton yarn. No person intending to purchase cotton yarn would be satisfied with sewing thread instead. Cotton yarn cannot be used in place of sewing thread or sewing thread in place of cotton yarn. These facts would be sufficient to treat cotton yarn and sewing thread as two distinct entities commercially. Therefore it will not be difficult to agree with the stand of the sales tax department that sewing thread does not fall within the scope of the entry 'cotton yarn' in item 4(ii) in the Second Schedule of the Act.
7. Counsel for the revision petitioner relies on the decision of the Orissa High Court in Srinivasa Distributing Agencies v. State of Orissa 1981 Tax. L.R. 2924, in support of the plea raised by him. But before we advert to this decision it is necessary to point out that the view that we have expressed here is consistent with the view expressed by this Court earlier. In Deputy Commissioner v. Khader Kunhi Sons  37 S.T.C. 227, the question this Court was called upon to consider was whether 'twisted cotton fishing twine' was the same as cotton yarn within the meaning of item 4(ii) of the Second Schedule of the Act. This Court noticed the decisions laying down the guidelines and in that background observed thus :
When cotton yarn is understood as the thin thread spun out of cotton which is utilised for the purpose of making twine, cord, rope, etc., would it be possible to call the particular article-the article is not before us now-cotton yarn. If the common man would not understand the substance sold by the dealer in these cases as 'cotton yarn' and if in the commercial world it is not known or could not be known as 'cotton yarn' the article would not fall under item No. 4(ii) of the Second Schedule to the Kerala General Sales Tax Act, 1963.
This view is consistent with the view expressed by the High Court of Allahabad in Mohta Trading Co. v. Commissioner of Sales Tax  38 S.T.C. 11, though earlier in Commissioner, Sales Tax v. Ballabh Das  25 S.T.C. 372 that court had indicated a contrary view. The principle of interpreting entries in the schedule being what we have indicated, we think that applying the above tests, we will be right in holding that sewing thread is not the same as cotton yarn. Now we will advert to the decision of the Orissa High Court relied on by the learned counsel for the petitioner. The learned Judges of the Orissa High Court rightly noticed the decision of the Allahabad High Court in Mohta Trading Company's case  38 S.T.C. 11. But after having done so and after having noticed the meaning of the terms 'yarn' and 'sewing thread', the learned Judges went on to observe thus :
A single yarn is capable of being used as sewing thread though if the material is cotton, for giving the thread considerable amount of strength, several yarns are rolled together. Between 'yarn' and 'thread', there is not much of a manufacturing process and the identity of the material is not lost. In fact, with a considerable amount of ease, the thread can be unrolled and restored to the earlier position of yarn.
We are afraid, with great respect to the learned Judges, we cannot agree. It may be theoretically possible to reconvert the sewing thread into cotton yarn from which it was made. But commercially one cannot imagine of any attempt to do so. It is not possible to say that sewing thread will be understood or used as cotton yarn. We are not concerned with the quantum of effort in the manufacture of yarn into thread. The fact that there is a process and the result of the process is to generate a new commercial product used for different commercial purpose than the component is sufficient to treat the two goods as of different identities for the purpose of the Sales Tax Act. A theoretical approach to the possibility of reconverting the goods into yarn even after manufacture of the thread-assuming that that is possible-will not answer the question before us. Commercial considerations and considerations of what happen in practice should guide the court rather than such theoretical possibilities.
8. A further contention has been raised by the learned counsel based on the plea of promissory estoppel and reliance is placed on the Orissa decision for that plea too. The decision of the Orissa High Court notices a letter from the Central Government construing the term 'cotton yarn' and according to the counsel for the revision petitioner based on this view expressed by the Central Government and adopted by the State Government later sewing thread was not being taxed as cotton yarn. It is said that the plea of estoppel succeeded under such circumstances and therefore it is not open, in the case before us, to the department to turn round and say that sewing thread also can be taxed otherwise than as cotton yarn. The plea is essentially that the State Government having conceded the stand earlier that sewing thread will fall within the scope of the term 'cotton yarn' in item 4(ii) of the Second Schedule they will be estopped from taking a different stand now and such estoppel based upon holding out a promise is a principle recognised by the Supreme Court as indicated in the decision in Motilal Padampat Sugar Mills Co. Ltd. v. State of U.P.  44 S.T.C. 42 (S.C.). We need not go into the question in this case whether such a rule of estoppel will operate against the provisions of a statute and whether holding out by any officer or even the Government in regard to the scope of operation of a taxing statute would estop the assessing authority from taxing in accordance with law. In this case we need go into that question only if we find that there is any scope for applying the rule of promissory estoppel. If there is none the further question whether promissory estoppel will operate in enforcing a taxing statute may not arise and if it is not necessary to dispose of the case we would not deal with it here.
9. A necessary ingredient of a proper plea of promissory estoppel is the averment as to a representation by way of holding out a promise and the other party acting upon that representation. If there is no case that a person has acted upon the representation of another the very basis or foundation of the plea of estoppel must be found to be absent. In the very decision to which the learned counsel for the revision petitioner adverted, the principle is explained thus:
The true principle of promissory estoppel, therefore, seems to be that where one party has by his words or conduct made to the other a clear and unequivocal promise which is intended to create legal relations or affect a legal relationship to arise in the future, knowing or intending that it would be acted upon by the other party to whom the promise is made and it is in fact so acted upon by the other party, the promise would be binding on the party making it and he would not be entitled to go back upon it, if it would be inequitable to allow him to do so having regard to the dealings which have taken place between the parties, and this would be so irrespective of whether there is any pre-existing relationship between the parties or not.
Again it is said thus:.where the Government makes a promise knowing or intending that it would be acted on by the promisee and, in fact, the promisee, acting in reliance on it, alters his position, the Government would be held bound by the promise and the promise would be enforceable against the Government at the instance of the promisee....
Further it is stated thus:.in order to invoke the doctrine of promissory estoppel, it is enough to show that the promisee has, acting in reliance on the promise, altered his position and it is not necessary for him to further show that he has acted to his detriment.
No doubt there is a case or the revision petitioner here that the Government made representation and further the stand now they are taking is contrary to such representation. But there was no case either before the Sales Tax Officer or at any time before the matter reached this Court that based upon any particular representation of the Government or promise of the Government the assessee altered his position by acting on the faith of it. So long as there is no such plea the question of promissory estoppel does not arise for consideration.
10. We therefore hold against the assessee on the question of the claim to non-liability to tax in regard to sales of sewing thread.
11. There are three more items of goods the turnovers in regard to which are said to be taxable. One of them is silk yarn. Silk yarn is not cotton yarn, though according to the counsel for the petitioner even silk yarn must be taken to be cotton yarn. This contention has only to be stated to be rejected.
12. The other two items are lace cloth and woven lace. Though in the revision petition a contention is taken up by the revision petitioner that these must be taken as cotton yarn the learned counsel for the revision petitioner does not pursue that contention. According to him, lace cloth and woven lace must be understood as cotton fabrics which is an item falling within item 7 in the Third Schedule, 'cotton fabrics'. The Third Schedule exempts certain goods from tax under Section 9 and one of them is cotton fabrics as denned in item 19 of the First Schedule to the Central Excises and Salt Act, 1944. That definition reads thus:
19. Cotton fabrics-
'Cotton fabrics' means all varieties of fabrics manufactured either wholly or partly from cotton and includes dhoties, sarees, chadders, bed-sheets, bedspreads, counterpanes, table-cloths, embroidery in the piece, in strips or in motifs and fabrics impregnated or coated with preparations of cellulose derivatives or of other artificial plastic materials but does not include any such fabric if it contains-
(i) 40 per cent or more by weight of wool;
(ii) 40 per cent or more by weight of silk;
(iii) 60 per cent or more by weight of rayon or artificial silk; or
(iv) 50 per cent or more by weight of jute (including Bimlipatam jute or mesta fibre).
Unfortunately we have no material in this case to understand what exactly are lace cloth and woven lace which are the goods in controversy. Whether they are made out of cotton or of silk, or partly out of silk or partly out of cotton are matters about which there are no materials before us. If the revision petitioner seeks exemption on the ground that these items fall within the Third Schedule to the General Sales Tax Act the burden is on the petitioner to prove this by placing materials before the authorities and rightly the Tribunal held that in order to find a commodity to be cotton fabrics the assessee has to prove that the commodity is cotton fabrics within the definition of item 19 of the First Schedule to the Central Excises and Salt Act. In this view no interference is called for on this count also.
In the result the tax revision case is dismissed. No costs.