As usual cyccommute proves that a little knowledge is a dangerous thing, and as usual won't admit he's wrong even when provided with factual evidence to the contrary.

Please just read an Engineering textbook. You can find some on Google books. Lbf and lbm don't just not exist because you think they're stupid. The world doesn't work that way.

btw the US government considers pound to be a unit of mass, and pound-force to be a unit of force.

http://physics.nist.gov/Pubs/SP811/appenB9.html