Belt Loops are meant to encourage the boys to "try out" a sports or academic activity. The Sports or Academic Pin is earned by the scout ON HIS OWN. These are totally optional awards for boys in Cub Scouts. It is usually up to the boy and his parent(s) to pursue these awards. On occasion, a Den or the Pack will do activities that coincide with belt loop requirements (i.e., rank requirements, arrow points, bowling trips, special events, etc.).
ALSO, the requirements for the Webelos activity badges of Athlete and Sportsman require the boys to earn a Sports pin and belt loops "while a Webelos scout" (per the book) - but our Pack policy allows pins and belt loops earned at any time during Wolf, Bear or Webelos to count toward these activity badges.
Boys will receive only ONE actual loop or pin per subject/sport during their time with the pack, but they can receive recognition at pack meetings as many times as they earn it.
LETTERS ... are no longer earned, they are simply purchased to display pins (totally optional).
The Pack Library has the new Belt Loop and Pin manual (an all-in-one manual now vs. the pamphlets on each), and the USSSP website (http://usscouts.org/advance/cubscout/a-s.html) also lists the requirements for each.