What does Herald stand for?

Heraldic (DIAR)

Harbor Echo Ranging and Listening Device

Helicopter Equipment for Radar And Laser Detection (SAUS)

Heterogeneous Experimental Reactor Aldermaston (SAUO)

Heterogenous Experimental Reactor, Aldermaston (SAUS)

Highly Enriched Reactor, Aldermaston - British (DEN)