If you mean the adjective 'well-noted' then it means well known ,famous as in a well-noted author. It could also be used as an expression, that something is well noted and it indicates that special attention should be paid or is paid to something. It could be added as comment or instruction (usually added at the end of an written article or said at the end of a professional conversation). When you say it ,you confirm you are paying special attention to the aforementioned points.