Rdl

Requirements and Development Language.
[“RDL: A Language for Software Development”, H.C. Heacox, SIGPLAN Notices 14(9):71-79 (Sep 1979)].

Read Also:

Rdml
rear admiral (lower half)
Rdna
rDNA Abbreviation of recombinant DNA ribosomal deoxyribonucleic acid
Rdp
protocol 1. Reliable Data Protocol. 2. Remote Desktop Protocol. (2004-09-14)