How whiteboards are extraordinary? (10)

I believe the answer is:

remarkable

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'are extraordinary?' is the definition.
(similar in meaning)

I can't explain the remainder of the clue.

(Other definitions for remarkable that I've seen before include "unusual" , "Noteworthy" , "A wrongly-graded exam paper" , "Striking" , "Extraordinary" .)

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

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