When starting a merit badge, always check the current edition of BSA Boy Scout Requirements
for the most up-to-date requirements. They may have changed since the booklet was printed.
As new pamphlets are issued, when they contain new requirements, Scouts have the option of starting with the new requirements as soon as the pamphlets are issued, or they may start work using the old requirements until the next edition of Boy Scout Requirements is issued. If a Scout starts work after a new edition of Boy Scout Requirements is issued, he must use the new requirements. In any case, once a scout starts with a set of requirements he can continue using them until he completes the badge or turns 18.
Changes to requirements, specific updates, and worksheets can be found at usscouts.org