What does RDH stand for?

Radioactive Drain Header - Nuclear energy (NRCH)

Rapid Displacement Heating - Pulp and paper technology

Recirculating Document Handler (SAUS)

Red Hill Marketing Group Ltd. - Vancouver Stock Exchange symbol

Reference Datum Height - Aviation (DA)

Registered Dental Hygienist

Remote Device Handler (IAA)

Resource Dispersion Hypothesis - Animal ecology

Ribitdehydrogenase (SAUS)

Round Head

Royal Deccan Horse - British military (DMA)