N.B. This should be written as N.B. This means that the colon or - or whatever, is not required because the full stop creates the break.
GrammerProof?? should that be GrammarProof? I expect it may be a trademark type name but, it may detract from your competence as grammar-savvy people.
"The day you stop learning is the day you become obsolete"! - my late Dad.
Why do some people say "I don't know for sure"? If they don't know for sure then, they don't know!
Useful MySQL resource
Useful MySQL link