It says that you cannot compete at another World or International Championship other then ICU or the USASF/IASF Worlds. So if a team from the US competes at the IFC event they cannot compete at Worlds or ICU. If a member of Team USA goes over with a team to the IFC competition they cannot compete with Team USA or a club team at Worlds. It also means that if Bangkok (or any other country) competes at the IFC event then they cannot compete at ICU or Worlds (many do both).
"It is therefore the policy of the USASF/IASF that no athlete, coach, judge, or official is permitted to participate in any way in any event that claims to be a World or International Championship, other than the ICU World Championships for National teams, or the USASF/IASF Worlds for All Star or Club teams.This stipulation applies to any regional international championship affiliated with an organization claiming to operate a World Championship, other than the ICU and USASF/IASF."