What is the NFL’s ‘legal tampering’ period for free agents?

For the next two days, NFL fans will be obsessed with “legal tampering.”

What the heck does it have to do with football, and with the league’s free agency period?

The two-day window will surely include a bevy of leaks and lasts from noon Tuesday until 4 p.m. Thursday when the actual free agency signing period and new league year begins.

The period allows agents to negotiate numbers, but not actually ink deals as the players cannot talk to teams. Players can talk to their own teams of course, and the “tampering” only applies to unrestricted free agents.