C-2 is one of those hidden and almost unknown programs developed when Amtrak was created. When Congress authorized the creation of NRPC in 1970, they realized that the probability of Amtrak being "self-sufficient and profitable" in five years, as the system was billed to accomplish, was in reality impossible. Since Amtrak was created to "create job opportunities" versus running passenger rail as many people think, the government created an independent "promise" to the new Amtrak employees (almost all being shed by the freight railroad payrolls) that if your craft were to become obsolete (abolished) due to the end of passenger railroading in the United States, the government will provide you money to "replace" your Amtrak income so you can restart your life, ie. go to school, learn a new trade, wait until you become eligable for retirement, RRB, Social Security, whatever. As BNSF1088 has already posted, there are formulas, charts, graphs, etc. that determine the dollar amount eligible. Also, as stated, it protects those in the private sector (freight railroads) employees from the effect of the loss of passenger railroad jobs (primarily T&E, clerical and ARSA jobs) and provide a means of acquiring new crafts to become employed in the freight side of railroading by on-board service employees.
It's worth noting that C-2 has been the most influential piece of legislation protecting passenger rail for over 35 years. Every Amtrak CEO from Reistrap to Gunn have used the government bailout of Amtrak employees to keep enough money in the pot for Amtrak not to have to abolish entire craft positions resulting in the abolishment of the high labor long distance trains. Which do you want? No trains and pay employees; Give Amtrak money and run trains using employees. It's a no brainer.
The key is that C-2 is a promise. Like any promise, it can be withdrawn at any time. All it takes is one paragraph in Amtrak's next reauthorization bill, and it's gone. Any employee should not view C-2 as a pension plan, that, like hundreds of other business, can drop like a hot potato and be turned over to the Guarantee Pension Board. C-2 is just a small, but important, part of Amtrak's Congressional charter. Like the micro-management of OBS services, C-2 could be abolished in one large package bill if Congress wanted to get rid of the "spur" Amtrak's used to defend the funding of the long distance trains. <_<