2 1. An apparatus comprising at least one processor and at least one memory including computer program code for one or more programs, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: receive or encode a bitstream comprising a coded picture, the coded picture comprising one or more tiles; identify one or more dependent tiles from the one or more tiles, wherein the one or more dependent tiles are dependent on another dependent tile within a coded picture or form a logical atomic unit with another dependent tile; construct an indication of an in-picture-prediction-enabled tile set comprising the one or more dependent tiles; and cause storage of the bitstream and the indication of the in-picture-prediction-enabled tile set. 22. An apparatus according to Claim 21, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus at least to: encode the indication of the in-picture-prediction-enabled tile set in one or more of: a sequence parameter set associated with the bitstream, a picture parameter set associated with the bitstream, or a supplemental enhancement information message associated with the bitstream. 23. An apparatus according to Claim 22 wherein the indication indicates whether the in-picture-prediction-enabled tile set is a temporal motion-constrained tile set. 24. An apparatus according to any of Claims 22 to 23 wherein the indication comprises a dependency forest or graph that indicates a set of prediction dependencies for one or more tiles that are not other non-in-picture predicted tiles to one or more tiles of the in- picture-prediction-enabled tile set. 25. An apparatus according to any of Claims 22 to 24, wherein the indication comprises a set of anchor positions for a set of intra block copy motion vectors of a set of dependent tiles in the in-picture-prediction-enabled tile set.