FFP standards - Wikipedia
The abbreviation NR or R is added after FFP1, FFP2, FFP3: NR (not reusable): if the use of the filtering half-face mask is limited to one working day. It is not reusable. R (reusable): if the filtering half-face mask can be used for more than one working day, so it is reusable. Additional suffixes include: Anti-clogging NR masks (D).