Henri, unfortunately you can't do what you are seeking to do. PAF, and all genealogical programs, relate everything to an individual or the marriage of individuals. Of course, it is possible with "cut and paste" to place the same Note in any number of individual records or marriage records.
A handy aid for doing this is Classic Clipboard. It extends the capabilities of Windows Clipboard immensely. You can store regularly used notes in huge quantities for retrieving to paste into records at some future time. I use it constantly every day. Find it at: http://www.easysoftwareuk.com/classic1.htmhttp://www.easysoftwareuk.com/classic1.htm And the best part about it, is that it is free!