{HEAD ~ At least a portion} of {TAIL ~ the catch} is positionable around at least a portion of the tab 
{ HEAD ~ At least a portion } of { TAIL ~ the catch } is positionable around at least a portion of the tab
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH