There's nothing about EF though. Does it mean 'R lens adapted to some mount' or 'Some lens adapted to R mount'?Come on guys! It's clear that ND and PL stand for filters (Neutral Density and Polarizing). The three adapter are:
M.ADAP R -> no filter
M.ADAP R ND -> with ND filter
M.ADAP R PL -> with PL filter
M can stand for M mount or for Mount, as the dot after the M suggest. In the second case EF lens will need this adpter to be used on the new R mount. That is.