For an unknown reason, several of the first programs to support SER disrespect the specification regarding the endianness flag. The specification states that a boolean value is used for the LittleEndian header, and they use it as a BigEndian header, with 0 for little-endian and 1 for big-endian. Consequently, to not break compatibility with these first implementations, later programs, like Siril and GoQat, have also decided to implement this header in opposite meaning to the specification.