Official rules interpretation: Face protection and knee braces
The correct interpretation of Rule 4:9 is that all types and sizes of
face (and head) protection are prohibited. In other words, the prohibition
concerns not only complete masks but also any protection for a part of the
face.
Continental and national federations are asked to adhere to this
official interpretation of the playing rules and to inform clubs and referees
as a matter of priority. It is not the prerogative of a federation, or a
referee, to make subjective judgments in individual cases.
Similarly, it is hereby made clear that knee braces made of hard, solid
material are prohibited. The safe, modern approach is to use braces of soft
material or, alternatively, the special form of taping that serves the same
purpose.
In principle, the above interpretations take effect immediately, and
must be applied at both the international and the national level as soon as the
information has been forwarded to the parties concerned.