On plate style runners, stiffening elements are controlled by specifications E.1.; E.1.d., e.,f.; E.4; E.6. and interpretations E. Runners dated 11/14/89, 7/1/92; four interpretations dated 1/15/2010; and I. Fittings dated 1/15/2010
Stiffening elements and reinforcement of the body of wood body runners are controlled by specifications E.2.a., d., e.; E. 4.; E. 6. and interpretations E. Runners dated 10/17/83; 11/23/87; 7/1/92; 11/30/98; four interpretations dated 1/15/2010; 12/01/2012; and I. Fittings dated 1/15/2010
On wood body runners, allowed material added to the body which is outside the allowed maximum body thickness of 1 1/32 inch (26.1 mm) is considered a runner stiffener or stiffening element. Allowed material added to the outside of the wood body, or in the slot of insert style runners, that does not exceed the allowed maximum body thickness of1 1/32 inch (26.1 mm) is considered external reinforcement.
Link to the new Interpretation of Official Specifications of DN IceYacht