DALLAS — Amanda Green knew precisely why she was having lunch Thursday in a 17th-floor restaurant accessible only to guests of the luxury hotel where she and the rest of the Oklahoma City Thunder organization were staying during their first-round playoff series against the Mavericks. In a sense, knowing why is part of her job.

“It’s in the collective bargaining agreement, that you have to stay at a certain class — level of hotels,” Green said over her vegetarian lunch.

Or, to quote from Page 266: “Each Team agrees to use its best efforts” to have players “stay in first-class hotels.” (Not surprisingly, teams are also urged to find accommodations that “have extra-long beds available.”)

Green, 31, who grew up in Queens, knows the 510-page agreement between the league and the players’ union pretty well as she nears the completion of her fourth season as the Thunder’s basketball operations coordinator.