Oddities Found in Old School D&D Rules

From the introduction:

These are not necessarily ERRORS nor FAULTS in the game. No book has ever been perfect and these were printed before the modern age of computers, often from hand written manuscripts which where typed by someone else which means various translation problems and miss-communications occurred from the start. They were often laid out by manual means, building pages by literally cutting them up with razors or scissors and pasting them together with glue and so on. Typo's occurred and fixing them was often hit-or-miss. Some errors were fixed in certain printings only to reappear again later. Whether or not something appears as noted can depend on your printing of a book. Errata was seemingly printed erratically.