(4)Regulation (EU) No 236/2012 imposes restrictions and obligations, such as notification and publication requirements, on natural or legal persons holding or entering into net short positions in shares and sovereign debt. Long and short positions in shares and sovereign debt can be held and valued in different ways. In order to ensure a consistent approach and give effect to the intention of the measures on short positions in shares and sovereign debt it is therefore necessary to further specify how net short positions should be calculated. Short sales may occur through single instruments or through baskets of sovereign debt and so it is necessary to specify how short sales through baskets are included in these calculations. In order to ensure a robust approach to the calculation of net short positions, it is necessary to apply a more restrictive approach to specifying long positions than short positions in shares. Because the value of some financial instruments depend on variations in the price of underlying instruments, it is necessary to specify how to account for this. The delta-adjusted methodology is specified since it is a commonly accepted practice.