HDL

The acronym HDL stands for

High-density lipoprotein, a protein for the transport of lipids, vulgo "good cholesterol"
Diploma commercial teacher, a graduate of the degree program in Business Education
Hardware Description Language, a formal language in information technology
HDL ( NDB ), the identifier of a radio beacon at Plank city
Fund of the German Lions, a service organization of all German Lions Club in support of major projects
High pressure fire-extinguishing system, a method in firefighting
The Last Hope, an Italian post-hardcore band from Ladispoli
Colloquially in chats Have You Dear, see list of abbreviations (network jargon ) # H

HDL as a distinguishing mark on license plate: