That the league is recognized by the USBC (United States Bowling Congress), formerly ABC (American Bowling Congress) as a league. The USBC is the sanctioning body in the US. It means that they are the ones that set the rules and make sure they are followed.
Only games bowled under a sanctioned league may receive recognition by the sanctioning organization that the league sanctioned with. For example, if the league is based in the US and did not sanction in USBC then scores will not be recognized for any USBC awards, including the 300 ring. Even if bowlers who are members of a non-sanctioned league bowl a 300, they can not qualify for any USBC awards if the league did not sanction.
Sort of. You can have a current sanction card from one league and bowl in another, non-sanctioned league. Your scores in the non-sanctioned league will not be recognized by the USBC, and you will not be eligible for any awards. However, bowling in the non-sanctioned league will not invalidate your USBC sanction, and you will be eligible for any awards earned in a sanctioned league.
Major league soccer is played in the U.S.A.
International Soccer League ended in 1965.
MLS is short for Major League Soccer which is the premier league of American soccer.
Island Soccer League was created in 2006.
Women's League Soccer was created in 2011.
Gippsland Soccer League was created in 1973.
World League Soccer happened in 1991.
Ultimate Soccer League was created in 2008.
Japan Soccer League ended in 1992.
Japan Soccer League was created in 1965.