1. Printer Control Language. A Document description language used by Hewlett-Packard Laserjet printers, a superset of HP-GL/2.

[PCL 5 Printer Language Printer Technical Reference Manual, HP 33459-90903. Versions: PCL 3, PCL 5].

2. Portable CommonLoops.

3. Peripheral Conversion Language. A Honeywell command language for file transfer between I/O devices on the CP-V and CP-6 operating systems.

4. ["PCL - A Process Oriented Job Control Language", V. Lesser et al, Proc 1st Intl Conf Distrib Comp Sys, IEEE 1979, pp.315-329].