This is one I have been thinking about recently. David says on GTD Fast that they have found that the best practice is for your @actions to be named after the physical contexts or locations where the NA will happen.
So, even If you work at a computer all day, you should still categorise actions as @computer if that is where you are going to do the NA.
If your computer and your phone are on your desk, it is better to use @phone and @ computer rather than a more global @desk.
At the moment I think this makes sense at a deep level, but I am not sure why yet.
I could for example use @Sage for our office in-house accounting, @Apex for accounting services for clients, @outlook for client communications, @hotmail for general newsletters received, @TaxPack for taxation services, @Ros for communications with the Inland revenue, @excel for additional accounting work and so on.
But I feel that this would dilute the emphasis that GTD places on Physical Action. The physical context of all of these is at the computer: differentiating between programs does not add any more clarity to the physical actions.
However, under the heading @computer I could happily list: “post January invoices”; “Recompute ABC ltd Tax charge”; "reply Ted re stock adjustments” and so on.
Don’t forget, David points out that most people come up with 30 to 100 projects. A good percentage of these will be put to one side under “Someday/maybe”, which means they do not have a related NA.
So you are down to, let’s say, thirty-five current work projects. Each one of these can have only one NA. They will probably spread between @phone, @computer, @anywhere, plus a few agendas for specific people.
Personal items shouldn’t have more than four or five physical categories also: @home, @other half (agenda); and one I find really useful is @on the road for when I might unexpectedly pass near a hardware, electrical or stationery store.
Even using this small number of categories, there shouldn’t be too much congestion under any one heading.
I think to key is to have just one NA for each project or sub-project. For example, if you have to call Susan about a possible program amendment, then only the phone call should be listed as the NA. You can’t also list the first step of the program amendment as an NA if you are not sure if you are going to go ahead with it yet.
Personally, I am going to try to keep my system as lean and simple as I can until I get the “martial art” just right!
Dave