If you have not installed the placard, assuming the AD applies to your glider, you glider is not airworthy and should not have passed the last annual or condition inspection.
It's easy to do. Print it, laminate(office tape will do in a pinch) and install with double stick tape.
Easy Peasy
UH

AD97-08-06 Note 1 "This AD does not apply to gliders and sailplanes that do not have a U.S. type certificate (i.e.., experimental category); however the FAA strongly recommends compliance with the intent of this AD for airplane involved in U.S. operation where a U.S. type certificate is not necessary.

Casey