Errata exists for this version of the document.

A ByteString is structurally the same as a one-dimensional array of Byte. It is represented as a distinct built-in data type because it allows encoders to optimize the transmission of the value. However, some DevelopmentPlatforms will not be able to preserve the distinction between a ByteString and a one-dimensional array of Byte.

If a decoder for DevelopmentPlatform cannot preserve the distinction it shall convert all one-dimensional arrays of Byte to ByteStrings.

Each element in a one-dimensional array of ByteString can have a different length which means is structurally different from a two-dimensional array of Byte where the length of each dimension is the same. This means decoders shall preserve the distinction between two or more dimension arrays of Byte and one or more dimension arrays of ByteString.

If a DevelopmentPlatform does not support unsigned integers, then it will have to represent ByteStrings as arrays of SByte. In this case, the requirements for Byte would then apply to SByte.