It looks like you have it in the thread. It’s on page 62 of the 2019 standards
EXTERIOR WALL is any wall or element of a wall, or any member or group of members, which defines the
exterior boundaries or courts of a building and which has a slope of 60 degrees or greater with the horizontal plane.
An exterior wall or partition is not an exterior floor/soffit, exterior door, exterior roof/ceiling, window, skylight, or
Good luck on your project….