A video processing method includes performing a conversion between a video block of a video and a coded representation of the video, wherein the coded representation conforms to a format rule, wherein the format rule specifies that applicability of a transform skip mode to the video block is determined by a coding condition of the video block, wherein the format rule specifies that a syntax element indicative of applicability of the transform skip mode is omitted from the coded representation, and wherein the transform skip mode includes, skipping applying a forward transform to at least some coefficients prior to encoding into the coded representation, or during decoding, skipping applying an inverse transform to at least some coefficients prior to decoding from the coded representation.