Erp, figure of Norse mythology

European Recovery Program, better known as the Marshall Plan

Enterprise resource planning, an Information Technology term referring to a hardware or software system that serves all departments within an enterprise

Engineer Recon Patrol, Warsaw Pact ground forces doctrine, a small detachment out in front of a mech or armored force identifying routes, obstacles and defense works

People's Revolutionary Army (Argentina) (Ejército Revolucionario del Pueblo)

Electronic Road Pricing, toll-collection scheme in Singapore

Erp (Netherlands)

Estonian Reform Party

People's Revolutionary Army (Mexico)

Effective radiated power, used in radio communications

Event-related potential, an electrophysiological response to an internal or external stimulus

People's Revolutionary Army (Colombia)

European Radio Project, a consortium of radio broadcasters working on a European public radio station.

Effective rate of protection, a method of working out the value of import tariffs

Exposure and response prevention, a psychotherapeutic method

"Emergency Response Plan", compulsory mostly for the large scale civil engineering construction works where there is a high risk of threat to the health, life and/or environment, see HSE.

Effective Refractory Period, (Medicine- Cardiac electrophysiology)

Erotic Role-playing, a sexual form of Role-playing (also Sexual roleplaying)

Erp (Germany), a village near Cologne

Economic Report of the President, published annually by the United States President's Council of Economic Advisors on recent economic activity and future policies and predictions.