Upgrading to stable, does it mean I have to reinstall ports packages?

["T." <tyskdisciplin@yahoo.se>]

Hello
 
You state in the FAQ that OpenBSD has three active versions and each one requires its own ports tree.
 
This should the mean that I have to reinstall all of my release version ports packages if upgrading to stable.
 
But when I look at the stable packages page (http://www.openbsd.org/pkg-stable.html) it does not offer any recompilations of all ports packages just the ones that need fixing. So my take is then that I shouldn't need to upgrade my ports packages when going to stable if they are not listed at the stable packages page.
 
I hope this is true, but I am not sure.
 
Thank you.