A video processing method is provided to include: determining, based on a position rule, whether a local illumination compensation (LIC) tool is enabled for a conversion between a current block in a video region of a video and a coded representation of the video, and performing the conversion based on the position rule. The position rule specifies that the LIC tool is enabled for blocks on boundaries of the video region and disabled for blocks inside the video region and the LIC tool includes using a linear model of illumination changes in the current block during the conversion.