Be keen. Sheets ordered. Excellent! (3,4,5)

I believe the answer is:

the bees knees

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'excellent' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.

'be keen sheets ordered' is the wordplay.
'ordered' is an anagram indicator.
'be'+'keen'+'sheets'='bekeensheets'
'bekeensheets' anagrammed gives 'THE BEES KNEES'.

Can you help me to learn more?

(Other definitions for the bees knees that I've seen before include "Excellent thing" , "Ideal person, event" , "Outstandingly good thing" , "joints used to crawl with insects?" , "A corker, a humdinger" .)

I've seen this clue in the Sydney Morning Herald.

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