This excerpt taken from the TSYS 10-Q filed Nov 7, 2007.
Our definition of backlog may not be the same as our competitors and there can be no assurances that the backlog will be realized.
Backlog represents an estimate of expected future revenue at any given point in time. Funded contract backlog represents contracts for which fiscal year funding has been appropriated by our customers (mainly federal agencies), and for our hosted services is computed by multiplying the most recent months recurring revenue times the remaining months under existing long-term agreements, which we believe is the best available information for anticipating revenue under those agreements. Total backlog, as is typically measured by government contractors, includes orders covering optional periods of service and/or deliverables, but for which budgetary funding may not yet have been approved. Our competitors may not define backlog in the same manner and a comparison to competitors backlog may not be meaningful.
Our backlog at any given time may be affected by a number of factors, including the availability of funding, contracts being renewed or new contracts being signed before existing contracts are completed. Some of our backlog could be canceled for causes such as late delivery, poor performance and other factors. Accordingly, a comparison of backlog from period to period may not necessarily be meaningful and may not be indicative of eventual actual revenue.