On my app, I did a brief 3 or 4 word summary of volunteer experiences, and I did a similar thing for work experiences. On most secondaries, you have a chance to expand a little and go into futher depth about your experiences. example:
Volunteer experience:
Soccer Coach, Boulder Jr. SOccer, Mar199-May2001. Independently coached 4th grade soccer team.
Work experience:
Trauma Tech, Boulder Hospital, July99-present. Clinical support provided to doctors and nurses.
And then in the secondaries, they ask you the same questions all over again, but give you a little more room to expand. Hope this helps.