/api/v0/swarm/peers direction translation?

The swarm/peers API can optionally return a direction element for each peer. I’m doing this and the values are 1 and 2 (0 if you don’t ask for direction in the request). I realize that these are likely inbound and outbound, but which one is which? And is this documented somewhere that I should be reading other than https://docs.ipfs.io/reference/http/api/