Welcome to uncharted waters.

To reduce the amount of blatant tampering that usually occurs before the start of the free-agent signing period, the NFL created a three-day negotiating window. It starts in a few hours. Here are the rules:

1. Beginning at 12 midnight Saturday and ending at 3:59 p.m. Tuesday, clubs are permitted to contact, and enter into negotiations with, the certified agents of players who will become unrestricted free agents upon the expiration of their 2012 Player Contracts at 4 p.m. March 12. However, a contract cannot be executed with a new club until 4 p.m. March 12.

2. During this negotiation period, a prospective unrestricted free agent cannot visit a club (other than the player’s current club) at its permanent facility or at any other location, and no direct contact is permitted between the player and any employee or representative of a club (other than the player’s current club). If a player is self-represented, clubs are prohibited from discussions with the player during the negotiating period.

3. Clubs (other than the player’s current club) may not discuss or make any travel arrangements with prospective unrestricted free agent players, their certified agents, or anyone else associated with the player until the expiration of those players’ 2012 Player Contracts.

4. The three-day negotiating period applies only to potential unrestricted free agents; it does not apply to players who are potential exclusive-rights players or restricted free agents, or to players who have been designated as franchise players or transition players.