One of the basic principles of the civil law of property is the numerus clausus principle 12 This means that only real rights, means of delivery of movables and modes of original acquisition of ownership that fall into one of the recognized categories, the numerus clausus, will be countenanced by the law. 13 Any new or additional real right thus falls outside the closed system (or numerus clausus) As far as the creation of new real rights is concerned, however, South African property law does not strictly adhere to this basic civilian principle. As a point of departure South African law falls back on the traditional categories of real rights acknowledged in Roman law(for example ownership, servitudes, mortgage and pledge). At the same time it accepts that new rights can be added and that within the framework of recognized categories new types can evolve. 14 Concerning the creation of new real rights, examples that have been added over the years include the lease of land, mineral rights and real rights in respect of units in a sectional title scheme Within the framework of the recognized categories of real rights mentioned above, several new types have evolved. In the context of servitudes one can mention new praedial servitudes which have developed due to typical South African cond itions(for example, the right of trekpath, the right of outspan and so-called restrictive cond itions in township developments), as well as a new type of personal servitude(the so-called servitudes irregulares). i5 In the sphere of real security the cession of registered mortgages as well as notarial bonds over movables have developed The abovementioned categories and extensions thereof received statutory recognition in the Deeds Registries Act, 16 in that the Act makes provision for the registration of these rights. 17 It should be pointed out that, in order for a right in land to have real effect, it must be registered in terms of the Act. The Act therefore deals with rights in land and it stipulates that only real rights in land are registrable. 18 However, the Act makes provision for the registration of real rights not specifically referred to in the Act 19 Consequently, a testator or a party to a contract is not 12Van der Merwe(n. 6)11f Van der Merwe and De Waal(n. 7)sect. 8 13/bid I4For the exposition that follows, see a lso Van der Merwe and De Waal(n. 7)sect. 45 SServitutes irregulares are personal servitudes with the contents of typical praedial serv itudes(for example, the rights of passage or pasturage ), but esta blished in favour of a particular person and not for the benefit of a dominant tenement 16Act47of1937 17Sect. 3(1) &Sect. 63(1 ). This section conta ins a proviso that a personal right may be registered if it is, in the opinion of the Registrar of Deeds, complementary or otherwise ancillary to'a registrable right. Such registration does not however, convert the personalright into a real right: D.G. Kleyn and A. Boraine Silberberg and Schoeman's The Law of Property (3rd ed. ) Butterworths, Durban(1992)162; N.J.J. Olivier, G.J. Pienaar and A J. van der Walt Law of Property: Students' Handbook(2nd ed. )Juta and Co., Cape Town(1992)236; Van der Merwe(n 6)477 19Sect. 3(1r)One of the basic principles of the civil law of property is the numerus clausus principle.12 This means that only real rights, means of delivery of movables and modes of original acquisition of ownership that fall into one of the recognized categories, the numerus clausus, will be countenanced by the law.13 Any new or additional real right thus falls outside the closed system (or numerus clausus). As far as the creation of new real rights is concerned, however, South African property law does not strictly adhere to this basic civilian principle. As a point of departure South African law falls back on the traditional categories of real rights acknowledged in Roman law (for example, ownership, servitudes, mortgage and pledge). At the same time it accepts that new rights can be added and that within the framework of recognized categories new types can evolve.14 Concerning the creation of new real rights, examples that have been added over the years include the lease of land, mineral rights and real rights in respect of units in a sectional title scheme. Within the framework of the recognized categories of real rights mentioned above, several new types have evolved. In the context of servitudes one can mention new praedial servitudes which have developed due to typical South African conditions (for example, the right of trekpath, the right of outspan and so-called restrictive conditions in township developments), as well as a new type of personal servitude (the so-called servitutes irregulares).15 In the sphere of real security the cession of registered mortgages as well as notarial bonds over movables have developed. The abovementioned categories and extensions thereof received statutory recognition in the Deeds Registries Act,16 in that the Act makes provision for the registration of these rights.17 It should be pointed out that, in order for a right in land to have real effect, it must be registered in terms of the Act. The Act therefore deals with rights in land and it stipulates that only real rights in land are registrable.18 However, the Act makes provision for the registration of real rights not specifically referred to in the Act.19 Consequently, a testator or a party to a contract is not 12Van der Merwe (n. 6) 11f.; Van der Merwe and De Waal (n. 7) sect. 8. 13Ibid. 14For the exposition that follows, see a lso Van der Merwe and De Waal (n. 7) sect. 45. 15Servitutes irregulares are personal servitudes with the contents of typical praedial servitudes (for example, the rights of passage or pasturage), but established in favour of a particular person and not for the benefit of a dominant tenement. 16Act 47 of 1937. 17Sect. 3(1). 18Sect. 63(1). This section contains a proviso that a personal right may be registered if it is, in the opinion of the Registrar of Deeds, ‘complementary or otherwise ancillary to’ a registrable right. Such registration does not, however, convert the personal right into a real right: D.G. Kleyn and A. Boraine Silberberg and Schoeman’s The Law of Property (3rd ed.) Butterworths, Durban (1992) 162; N.J.J. Olivier, G.J. Pienaar and A.J. van der Walt Law of Property: Students’ Handbook (2nd ed.) Juta and Co., Cape Town (1992) 236; Van der Merwe (n. 6) 477. 19Sect. 3(1)(r)