Keith Burgess-Jackson writes, "First there was a copy; then there was an electronic copy; then there was a physical copy."
To which I add: First I had a plain old address; then I acquired an e-mail address, so that now my plain old address is a physical address.
Should we speak of retronymic families? 'Physical address' and 'snail mail' belong together in one family, 'acoustic guitar' and 'acoustic set' in another.