Reversible nesting and stacking container

Claim 1

A TRAY COMPRISING A BOTTOM HAVING THE SHAPE OF A RECTANGLE, SIDE WALLS PROJECTING UPWARDLY FROM THE EDGES OF SAID BOTTOM, A RECTANGULAR LIP FORMED AT THE UPPER EDGE OF SAID SIDE WALLS, SAID LIP HAVING HIGHER PORTIONS AND LOWER PORTIONS ARRANGED IN A PATTERN AROUND SAID TRAY AND ARRANGED TO INTERLOCK WITH PORTIONS OF A LIKE TRAY WHEN TWO LIKE TRAY ARE PLACED LIP TO LIP TO FORM A CLOSED RECEPTACLE, SOME OF SAID HIGHER PORTIONS BEING LATERALLY INWARD AND SOME LATERALLY OUTWARD RELATIVE TO SAID RECEPTACLE, EACH SAID HIGHER AND LOWER PORTION EXTENDING GENERALLY PARALLEL TO ITS ASSOCIATED SIDE OF SAID RECTANGLE, FROM EACH OF THE CORNERS OF SAID RECTANGULAR LIP IN THE SAME HAND DIRECTION ALONG AN ADJACENT SIDE THERE BEING ONE OF SAID HIGHER PORTIONS EXTENDING A PREDETERMINED LENGTH FROM SAID CORNER, THE SIDE PARALLEL TO EACH SAID ADJACENT SIDE HAVING A LOWER PORTION LATERALLY OPPOSITE SAID ONE HIGHER PORTION AND OF SAID PREDETERMINED LENGTH, SAID PATTERN INCLUDING ON OPPOSITE PARALLEL SIDES OF SAID RECTANGLE SUCH COMPLEMENTARY POSITIONING OF SAID HIGHER AND LOWER PORTIONS, WHEREBY IN CLOSED-RECEPTACLE-FORMING POSITION THERE BEING TWO OF SAID HIGHER PORTIONS ABUTTING EACH OTHER AT A PLURALITY OF POSITIONS ALONG EACH SIDE OF SAID RECTANGLE IN A DIRECTION AT RIGHT ANGLES TO SAID PORTIONS SO AS TO POSITIVELY PREVENT DISPLACEMENT OF SAID TRAYS IN SAID POSITION BY A LATERAL PUSH, AND ALL PARTS OF SAID TRAY CONSTRUCTED AND ARRANGED TO NEST WITH A LIKE TRAY IN LIKE ORIENTATION.