Most motor gliders can be either a TMG or an SLMG.
I "think" that any glider with a stow away prop or engine ( Nimbus DM, DG's, Stemme etc) can only be an SLMG.
Its all a bit of a pain, as I hold both both an NPPL and a UKPPL, so the two 'planes I fly ( Pawnee and RF5 ), can be either SSEA and SLMG,or SEP and TMG.
I undestand other countries within europe and the rest of the world do not have such distinctions