Please verify this.

Believer wrote:

Hi, I think I heard from somewhere that a person should use a colon to introduce a vertical list only if a person could use a period (as a matter of common sense?). I don't understand what you mean. If that is true, would you say all these uses of the colon I saw so many times are wrong?  The things we need to heed are: I would NOT do this. Either "What we need to heed:" followed by a bulleted list, or simply remove the colon and continue on with the list We need to address such topic area as: This one is questionable. I'd want to see more context. In this course, you will find:  This is fine - what follows should be all noun phrases.