This is kinda an extension to: this question.
I am writing a scientific paper and have a numbered list. Now, when I want to refer to that list I want to say something like: "This issue is closely related to item number 12."
As a non-native I'm not sure whether that sounds 'normal' or if it would be easier to read with "no. 12" or "#12" or option number(?) three, just "item 12".