A method of video processing is described. The method includes: making a first determination about whether a collocated video block of a video block of a video is coded using an inter coding mode or a non-inter coding mode; making a second determination, based on the first determination, about availability of motion vectors of the collocated video block or a mode of derivation of motion vectors for the collocated video block; and performing a conversion between the video block and a coded representation of the video based on the second determination.