Would someone with experience be kind enough to comment on exactly how the proper range is marked?

Have seen various overlapping/contradicting items online that consider either the smaller square the proper range (a comment online), the long rectangle the proper range (less-than-clear owners manual drawing), and both shapes combined the proper range - with the common central border the ideal "center" to point at (a multi-year TSX service manual graphic).

 

See attached

 

Well mine certainly looks in range. Guess I'll have to use that wet-it-with-water trick seen here to see if the squeal is from the belt itself.
Thanks for posting that graphic - it confirms what I'd seen in a Service Manual found online. It's more explicit (the inset) and shows a wider range than the Owner's Manual diagram (attached).
Out of curiosity, would anyone know in which direction the pointer would "move" as the belt loosens/gets less tense? (If the owners manual drawing is simply more strict than the service manual, I'd guess towards the right into the square)

 

mine as making noise when cold, local mechanic put some lube on it, not too much, and all is good now.