TwoLatinsquaresofordervarer-orthogonaliftheirsuperpositionproducesexactlyrdistinctorderedpairs.Thetwosquaresaresaidtober-orthogonalidempotentLatinsquaresanddenotedbyr-MOILS(v)iftheyareallidempotent.Inthispaper,weshowthatforanyintegerv≥28,thereexistsanr-MOILS(v)ifandonlyifr∈[v,v~2]\{v+1,v~2-1}.