0x010xFF
0x010xFF is not a standard single hex literal in most programming languages. It is typically interpreted as a sequence of two hexadecimal bytes: 0x01 and 0xFF. Such a two-byte sequence can represent a 16-bit quantity when considered as a single value, or it can be used as two separate fields within a binary format.
If interpreted as a 16-bit unsigned integer in big-endian (network) order, the value of the two-byte sequence
In practical contexts, a two-byte sequence like 0x01 and 0xFF may appear in binary protocols, file formats,
In character encodings, 0x01 is a control code (Start of Header in ASCII), while 0xFF corresponds to
Because 0x010xFF mixes two hex literals, it is typically a documentation shorthand or a typographical quirk