Art. 13(4), added in 2003 to Art. 13 (Capital gains) of the OECD Model Tax Convention, deals with the alienation of shares deriving more than 50% of their value from immovable property situated in a contracting state. After considering the nature and purpose of Art. 13(4), this article examines various aspects of the provision, including (among others): shares deriving value from immovable property, the definition of immovable property, determining the sources from which the shares derive their value, when the 50% test must be satisfied, and the compatibility of the "deriving value" test with the purpose of Art. 13(4).