A-100 – The initial training class all new FSOs go through.
CBP – Customs and Border Patrol
CDJ – Ciudad Juarez
DHS – Department of Homeland Security
DOS – Department of State
ELP – El Paso
HHE – Household Effects – your stuff that DOS will ship to post by surface (boat, truck, train, etc.)
IV – Immigrant Visas
NIV – Non-immigrant Visas
UAB – Unaccompanied Air Baggage (I think) – the shipment of stuff that is delivered to you at post by air freight and that usually arrives much faster than your HHE.
USCIS – U.S. Citizenship and Immigration Service
WHA – Western Hemisphere Affairs – Department of State bureau that covers countries in North and South America and the Caribbean.