This proposed addendum clarifies Section 5.9.2 regarding the conditions under which the ventilation system must be operated to provide exfiltration. It also proposes a change to the definition of 'exfiltration' in Section 3 and modifies Section 6.2.7.1.4 to require compliance with 5.9.2, rather than restating requirements which may possibly become inconsistent with 5.9.2.