Here you go zod
Signing bonuses are exactly what they sound like. It is a bonus that is paid directly to the player at the time of signing his contract. For cap calculation purposes, the signing bonus is “prorated” over the life of the contract. This simply means that the amount of the signing bonus is spread out over the years of the contract evenly. So a $5 million signing bonus on a 5-year contract will count $1 million per year against the cap. Again, this is only for cap purposes – the player has already received this money. Signing bonuses are guaranteed and cannot be recouped except in extremely rare circumstances (think Atlanta vs. Mike Vick). The max proration for a bonus is 5 years. This is done so that teams can’t sign 10 year contracts to help alleviate the bonus hit."