PGDP does a series of passes on a book. They don't continually update it. If a book makes it through their process with a typo, or more common, made it through

PGDP does a series of passes on a book. They don't continually update it. If a book makes it through their process with a typo, or more common, made it through the transcription process 20 years ago, there aren't good systems in place to fix those issues.