mean that relationships which start as being contractual in nature may go through a metamorphosis and end up being, at least in part, proprietary in nature. 2I The very moment however, the swap has to be executed(e. g. through netting ), it would, in this respect, still be a contract. The result of the metamorphosis would then be a legal relationship of a hybrid nature 22 I will not on to y further into this; I would only like to point out that if this really would be the case for reasons of clarity and certainty a formal line should be drawn between the contractual side and the commod ities side of a derivative. a suggestion for the drawing of this formal line may be that a derivative becomes(at least in part )a commod ity once it has been standard ised and for that reason can be traded almost anonymously at an exchange. An advantage of this formal approach is that the proprietary side of the derivative will be clearly separated from its contractual side. The proprietary side could, to offer an illustration, only be reflected in the formalities required for the transfer of the derivative-the acceptance of screen trading as a new form of (instantaneous) transfer next to, e. g assignment and the handing over of a bearer document-without influencing matters like netting. It will be obvious that such questions, as I can only outline here, are of a perplexingly complicated nature. In the following pages I will only focus on the numerus clausus as such and not on the object of absolute rights, includ ing the borderline between contract and property For civil lawyers, the numerus clausus doctrine is a basic element of property law. 2 For a better understand ing of what follows, it may be useful to reiterate what the numerus clausus doctrine is, in the light of other basic elements of civil property law, before we contrast civil law with common law. Accord ing to the numerus clausus doctrine the number of absolute rights is limited their content is restricted and it is laid down in mandatory rules including exchange-traded derivatives. CfK Medjaoui, Les marches a terme derives et organises d'instruments financiers Etude juridique (Paris: L.G.D., 1996), pp 261 ff, where a discussion can be found about the(my translation )definition of and distinction between a futures"contract"and a negotia ble option: the products'. On p. 268, Medjaouimakes the following remarks, which show how troublesome the qualificationcontractor'commodity proves to be: Ainsi, pour une meme valeur, plusieurs options et contrats, d'identification equivalente dans leur qualite, quantite, echeances, vont etre crees et admis a la negociation. s'agit de produits fongibles, dans leurs caracteristiques qualitatives et quantitatives intrinseques;soit une caracteristique commune a ux valeurs mobilieres, mais le rapprochement s'armete la. He adds(p 283) Ces produits a terme ne sont pas des valeurs mobilieres, bien que certa ins emploient, a tort, Iexpression d em ission, pour qualifier leur creation. Cette vision est fausse et risque d'entretenir des confusions, non seulement par rapport a la procedure de creation de ces produits d'une part, mais aussi quant a leur contenu juridique, confronte a celui d'une valeur mobilier, principalement une action See, for a comparable problem area(immobilisation of securities), R. Goode, The Nature and Transfe Financial Law(1996), 167ff. Particularly interesting is the analysis of possible characterisations of entitlements hich a depositor of securities might have towards the institution which holds the securities, e.g a bank( goode loc. cit, pp. 170 ff.) The following can only be a very general and superficial overview of some basic aspects of civil property law. Of course, differences exist between the various civ il law systems. I need only refer to the acceptance of so-called"Anwartschaftsrechte under German law, which are seen as quasi-real rights (Anwartscha are, literally translated, expectation rights, such as the right of the buyer under a retention of title clause, a buyer expects to become owner afterpayment of the purchase price.)mean that relationships which start as being contractual in nature may go through a metamorphosis and end up being, at least in part, proprietary in nature.21 The very moment, however, the swap has to be executed (e.g. through netting), it would, in this respect, still be a contract. The result of the metamorphosis would then be a legal relationship of a hybrid nature.22 I will not go any further into this; I would only like to point out that if this really would be the case, for reasons of clarity and certainty a formal line should be drawn between the contractual side and the commodities side of a derivative. A suggestion for the drawing of this formal line may be that a derivative becomes (at least in part) a commodity once it has been standardised and for that reason can be traded almost anonymously at an exchange. An advantage of this formal approach is that the proprietary side of the derivative will be clearly separated from its contractual side. The proprietary side could, to offer an illustration, only be reflected in the formalities required for the transfer of the derivative - the acceptance of screen trading as a new form of (instantaneous) transfer next to, e.g., assignment and the handing over of a bearer document - without influencing matters like netting. It will be obvious that such questions, as I can only outline here, are of a perplexingly complicated nature. In the following pages I will only focus on the numerus clausus as such and not on the object of absolute rights, including the borderline between contract and property. For civil lawyers, the numerus clausus doctrine is a basic element of property law.23 For a better understanding of what follows, it may be useful to reiterate what the numerus clausus doctrine is, in the light of other basic elements of civil property law, before we contrast civil law with common law. According to the numerus clausus doctrine the number of absolute rights is limited, their content is restricted and it is laid down in mandatory rules including exchange-traded derivatives. 21 Cf. K. Medjaoui, Les marchés à terme dérivés et organisés d’instruments financiers. Étude juridique (Paris: L.G.D.J, 1996), pp. 261 ff., where a discussion can be found about the (my translation) ‘definition of and distinction between a futures “contract” and a negotiable option: the products’. On p. 268, Medjaoui makes the following remarks, which show how troublesome the qualification ‘contract’ or ‘commodity’ proves to be: Ainsi, pour une même valeur, plusieurs options et contrats, d’identification équivalente dans leur qualité, quantité, échéances, vont être créés et admis à la négociation. Il s’agit de produits fongibles, dans leurs caractéristiques qualitatives et quantitatives intrinsèques; soit une caractéristique commune aux valeurs mobilières, mais le rapprochement s’arrête là. He adds (p. 283): Ces produits à terme ne sont pas des valeurs mobilières, bien que certains emploient, à tort, l’expression d’émission’, pour qualifier leur création. Cette vision est fausse et risque d’entretenir des confusions, non seulement par rapport à la procédure de création de ces produits d’u ne part, mais aussi quant à leur contenu juridique, confronté à celui d’une valeur mobilière, principalement une action, d’autre part. 22 See, for a comparable problem area (immobilisation of securities), R. Goode, ‘The Nature and Transfer of Rights in Dema terialised and Immobilised Securities’, Butterworths Journal of International Banking and Financial Law (1996), 167 ff. Particularly interesting is the analysis of possible characterisations of entitlements which a depositor of securities might have towards the institution which holds the securities, e.g. a bank (Goode, loc. cit., pp. 170 ff.). 23 The following can only be a very general and superficial overview of some basic aspects of civil property law. Of course, differences exist between the various civil law systems. I need only refer to the acceptance of so-called ‘Anwartschaftsrechte’ under German law, which are seen as quasi-real rights. (‘Anwartschaftsrechte’ are, literally translated, expectation rights, such as the right of the buyer under a retention of title clause; a buyer expects to become owner after payment of the purchase price.)