The comments must be usefull, meaning, the Asker must be able to solve his Issue due to your Answer. Or if its a Trading Question, the answer must be precise, meaning, include Data that you used to reach your answer, and also, avoid criticise any action or trade, since its allways a decision of free will, and what is expected is an alternative answer to the same result, that is both usefull for the trader(s) and also is viable and veryfiable by anyone.
Dukascopy Bank expects the comments to be sensible and meaningful. The comment should reflect the grounds or factors that drove the trader to effectuate the particular trade.
Senseless, run-around comments are not tolerated. Even though Dukascopy will not delete them unless they contain any sort of abuse, advertisement or any other kind of spam, the trader has to be aware that a predominance or considerable share of ineligible comments will significantly decrease his odds to receive any extra bonus points when being analyzed by the Dukascopy evaluation committee (4th factor of the total score).