performing a conversion between a video region of a video and a bitstream of the video,

wherein whether a merge mode is applied is determined,

wherein whether an intra block copy (IBC) motion vector prediction mode is applied is determined,

wherein, when the IBC motion vector prediction mode is applied and the merge mode is not applied, whether to include at least one syntax element for the IBC motion vector prediction mode in the bitstream is based on a maximum number of IBC candidates used during the conversion of the video region,

wherein the at least one syntax element includes a motion vector predictor index of list 0,

wherein list 0 is a reference picture list of the video region with a reference picture list index of 0,

wherein, when the IBC motion vector prediction mode is applied, samples of the video region are predicted from other samples in a video picture comprising the video region,

wherein, when the IBC motion vector prediction mode is applied and the merge mode is not applied, a vector of the video region is derived based on a motion vector predictor and a motion vector difference,

wherein the motion vector predictor is determined based on the motion vector predictor index of list 0,

wherein, when the maximum number of IBC candidates is equal to zero, the IBC motion vector prediction mode is disabled,

wherein, when the IBC motion vector prediction mode is enabled for a slice comprising the video region, the maximum number of IBC candidates is greater than zero, and

wherein, when the merge mode is applied to the video block and the IBC mode is applied to the video block, a vector of the video region is derived based on the motion vector predictor.