A method of video decoding for a decoder is provided. In the method, prediction information of a block of a coded region in a video is coded from a coded video bitstream. The prediction information includes high level signaling information. A determination is made as to whether a prediction mode of the block is an intra block copy (IBC) mode based on a value of the high level signaling information and constraint information. The value of the high level signaling information is indicative of a maximum number of motion vector prediction candidates in a motion vector prediction candidate list for the IBC mode. The block is thus decoded based on whether the prediction mode of the block is determined as the IBC mode.