Up til recently I've always assumed that people credited songs "trad" in the absence of a composer's name. But having listened to some Jon Raven stuff recently I notice he uses the two terms above

I know Jon often took lyrics from broadsides & ballad books and set them to traditional tunes, so in effect he was creating something new from old sources, and presumably he didn't necessarily feel these could be deemed part of the oral tradition. But Martin Carthy's being doing that for years, and yet his stuff is "Trad arr Carthy"

Have I got the wrong end of the stick with this? Can you call something traditional if you've no evidence that anyone ever sang it? This could perhaps apply to some of the longer Child Ballads, but I could be wrong