Please keep example

Hello peoples,
i want to use the bridge/filter/802.3
DSAP, butwhen i set the value to AA, i receive the following:
Couldn’t add new bridge filter rule -802.3 matchers valid only for length ethernet protocols(6)

What it mean, and who can help me with examples of using this point.
P.S> I don’t find nothing in google, only mikrotik manual… :frowning:

try mac-protocol=1