The ruling on which you seek more information follows.
Players who are participating in any high-school level program such as a high school freshman, JV-B, junior varsity, varsity or club team should not be eligible for U15 competition in the same season. This means that a player who is age-eligible for U15 but plays on a high school level team should not concurrently play on a youth league U15 team. At other times of the year this player may be U15 eligible, for example, for summer ball or fall ball play, depending on the guidelines of the sponsoring league or organization.