In TC #22 we agreed to amend #204 by making region.charOffset and region.byteOffset nullable integers instead of plain integers, so that consumers could distinguish a missing property from a 0-valued property. In a phone call last week, Michael, Jim and I reached the conclusion that this is not necessary, and the distinction can be made at the SDK level rather than at the file format leve. A JSON deserializer such as Newtonsoft.Json can already do the following: On input, distinguish between a missing property and a zero-valued property On input, specify a default value for a missing property. On output, specify that a property with the default value not be serialized. So in the SDK, we just have to specify the otherwise-unused value -1 as the default value of region.charOffset and region.byteOffset , and to specify that those properties not be serialized if they have the default value. There is no need to change the spec. I merged the changes for #204 into the provisional draft without making the changes to nullable integers. Since this is not what we agreed in TC #22, I will add an agenda item to allow the TC to ratify this change. Thanks, Larry