what rules are those?
The following is taken from the FA website.
Post Brexit, clubs will not be able to sign players freely from the EU. Players from EU countries who want to play in the Premier League or EFL will be required to gain a GBE, like all other overseas players without the right to work in the UK.
The GBE will operate a points-based system, where points are scored for senior and talented young players based on:
• Senior and youth international appearances
• Quality of the selling club, based on the league they are in, league position and progression in continental competition
• Club appearances, based on domestic league and continental competition minutes
Players accumulating the requisite amount of points will earn a GBE automatically, while players just below the threshold may be considered for a GBE by an Exceptions Panel.
The system meets the joint objectives of the Premier League, EFL and the FA allowing access to the best players and future talent for clubs, as well as safeguarding England teams, by ensuring opportunities for homegrown players.
In the Premier League, the number of overseas U21 players a club can sign will be limited to three in the January transfer window and six per season moving forwards. This enables the recruitment of the best players from around the world to train and play together with homegrown talent. Under FIFA’s rules, the UK’s exit from the EU will also mean that clubs will not be able to sign players from overseas until they are 18