Devices, systems, and methods for lossless coding for visual media coding are described. An exemplary method for video processing includes determining, based on a current video block of a video satisfying a dimension constraint, that coding modes are enabled for representing the current video block in a bitstream representation, where the dimension constraint states that a same set of allowed dimensions for the current video block is disabled for the coding modes, and where, for an encoding operation, the coding modes represent the current video block in the bitstream representation without using a transform operation, or where, for a decoding operation, the coding modes are used to obtain the current video block without using an inverse transform operation; and performing a conversion between the current video block and the bitstream representation of the video based on one of the coding modes.