I came across this website, and it has different descriptions of picking techniques, and here’s what it says about crosspicking:
“6. Cross picking
This is a style often or mainly used in Bluegrass music on guitar, mandolin and sometimes on the banjo if not played with finger picking. It’s a different feel and phrasing than what is achieved with alternate picking.
The strokes used are D D U D D U D U or U U D U U D U D. (D = down-stroke, U = up-stroke)
Advantage:
It results in the correct articulation for forward and backward rolls when not done with finger picking.
Disadvantage:
Probably the technique with the most heavy duty string-crossing.”
http://www.hodosy-music.com/flatpick.html
Does this sound right?