swimwear with side cords

[Byron]

I have noticed a tendency of Rufskin (and maybe others) to open the drawstring to the far left of centre now in the waist band (never far right to my knowledge).
You might however be referring to simple tie cords at the hips as with the girls' bikini bottoms. Then again you may be referring back to the old designs of the early sixties where long laces in a lattice (much like boot laces) were provided
at left or right hips, or both.