Rather than poster X saying, "I think satin's sibling is Y", I
suggest that any poster who tries this challenge detail the elements looked for as evidence of familial ties. This
could include shared idioms or cultural references.

I have to admit to being confused a bit, max (he digressed, futilely attempting to return to the challenge) -- just how are we to "detail the elements" without, in effect, posting a guess as to identity??