The DD's or Device Description files follow:
AABB.ffo
AABB.sym
Where AA is the DEV_REV (device revision) and BB is the DD Revision (file revision).
The CFF or Capability File follows:
AABBCC.cff
Where AA is the DEV_REV (device revision); BB is the DD_REV (from device RB.DD_REV parameter - typically "01"); CC is the CFF revision (file revision).