 Since this is the point where the encoder increases the code width, the decoder must increase the width here as well—at the point where it generates the largest code that fits in "p" bits.Unfortunately, some early implementations of the encoding algorithm increase the code width and "then" emit ω at the new width instead of the old width, so that to the decoder it looks like the width changes one code too early.This is called "early change"; it caused so much confusion that Adobe now allows both versions in PDF files, but includes an explicit flag in the header of each LZW-compressed stream to indicate whether early change is being used.