- PDH
- Plesiochronous Digital Hierarchy (Computing » Telecom)Plesiochronous Digital Hierarchy (Computing » Networking)**** Professional Development Hours (Business » Positions)** Professional Development Hour (Business » Positions)* Procuraduría de Derechos Humanos (International » Guatemalan)* Pituitary-Dependent Hyperadrenocorticism (Medical » Physiology)* Performance Data Helper (Computing » General)* Peterborough District Hospital (Medical » Hospitals)* Pain Drug Hypnosis (Medical » Physiology)* Prevention of Deafness and Hearing Impairment (Medical » Physiology)
Abbreviations dictionary. 2012.