Between Feb. 18 and March 4, each NFL team was permitted to use the franchise tag to prevent one player from becoming an unrestricted free agent later in the spring.
Eight tags were used in total, which gave tagging teams a four-and-a-half-month negotiation window in which to sign their tagged players to long-term deals. After that, it's either an automatic one-year contract based on the average of the top-five salaries for whatever position they play, or it's a holdout (and sometimes, ultimately, it's both).
That window will close on Monday at 4 p.m. ET, and none of the eight tagged players have signed long-term deals yet.