portupgrade questions

[Donovan R. Palmer]

> While portsupgrade does work on packages it is usually better to do
> stuff from ports... even though this may be time consuming you may want
> to deinstall every last package you have installed then select a few
> "high level" ports to install (i.e. enough to drag in almost everything
> you need)... in general the install cycle I use is:
>
> 1. Install a top-level port (making any build changes needed if build
> fails [*PLEASE* submit a pr for any of these])
> 2. Do a csup (or cvsup on older releases) to make sure there is nothing
> newer for the installed ports
> 3. Do a portupgrade -a
> 4. If there are more top-level ports goto to step 1

Very interesting.  Without sounding too daft, how do I determine what a 
"high level" port is?  Thanks!