From the back of the book:
"Pirate or Merc?
Kell Hounds. Northwind Highlanders. Blue Star Irregulars. Literally a thousand and one mercenary units populate the Inner Sphere, yet these are the house hold names that capitivate the common man. But for every top, there is a bottom. Gray's Ghosts. Kraken Unleashed. Vinson's Vigilantes. Some call them 'pirates,' othhers 'down-on-their-luck,' and others 'salvation' when the job's small enough and the pay just right. But for these hard-boiled warriors life isn't cheap. Life hard exists at all!
A companion volume to Classic BattleTech Field Manual: Mercenaries, Revised, and Mercenaries Supplemental, Mercenaries Supplemental II delves into the dregs of the mercenary world, allowing players to use these unique mercenaries in their Classic BattleTech campaigns. Additional rules for mercenary creation include non-BattleMech Unit Tech Levels, special renegade and freelancer mercenary paths, as well as rules for playing mercenaries in different BattleTech eras, from the Star League, to the Succession Wars, to the present."