Lines
Many contracts carry performance bonuses: extra pay if a player hits a games-played mark, makes an All-Star team, wins an award. The league sorts every bonus by last season. If the player met the criteria then, the bonus is "likely" and counts like regular salary. If he didn't, it is "unlikely" and stays off the cap and tax numbers unless he actually earns it.
Unlikely bonuses do count against the two apron lines. So a team's apron figure is its payroll (contracts, dead money, and drafted rookies) plus its unlikely bonuses, and a team with real bonus money sits closer to the aprons than its payroll suggests.
That matters most for hard caps. A team hard-capped at an apron measures its room with unlikely bonuses counted, which can be the difference between a legal move and an illegal one.
See it live: pick any team and tap the numbers on its cap sheet.