Thanks for the effort, but that "Not sure" Note comment is not actionable. 

In StreetComplete, when you choose "Can't say..." it will give you an option to "Hide" the quest, or "Leave note". 

If you can provide more information, please do use "Leave note" and provide it! 

However, if you just don't know and cannot provide more information which would result in improved map, then please just choose "Hide". Thanks!

#notenoughinfo 