Pre-contract agreements - why are they different in NI?
They have become part and parcel of the January transfer window over recent years - pre-contract agreements.
Deals made mid-season between clubs for the transfer of players nearing the end of their contracts at the end of the campaign have become commonplace across Europe.
Interestingly though the Irish League adopts rules that are not applied in some other major leagues including the Premier League, meaning that players can agree moves within the same jurisdiction, that is to other Irish League clubs.
BBC Sport NI assesses some of the issues surrounding pre-contracts and how they have affected the domestic game in Northern Ireland.
What are pre-contracts?
A pre-contract arrangement is when a player agrees to join a different club at the expiry of their current contract.
After the interested club provides written notice of their intent to do so, discussions can begin up to six months before the end of a player's current deal.
A player who is approaching the end of their contract can sign with another club without incurring any transfer fees.
The rule was established in accordance with the 1995 Bosman ruling concerning the freedom of movement rights of professional footballers.
Why are the rules different in NI to the Premier League?
The Irish FA has indicated that the rules followed in Northern Ireland reflect the guidelines set out by football's world governing body, Fifa, which allow negotiations to happen between a player and other clubs in the same league.
In the Premier League, the rules are somewhat different.
The FA regulations stipulate that players in the last six months of their contract can only speak to clubs in other nations.
They must wait until the final month of their contract before speaking to other domestic clubs.
One reason for this may be with sporting integrity in mind, ensuring that there is no conflict of interest between clubs working under their remit.
In response to a BBC Sport NI request about why the rules in Northern Ireland differed from the Premier League, an IFA statement read:
"Certain provisions within the Fifa Regulations and Status of Players (RSTP) regulation are binding at national level and must be included without modification in national association's regulations.
"This includes the following RSTP text in respect of special provisions relating to contracts between a professional player and clubs:
"A club intending to conclude a contract with a professional must inform the player's current club in writing before entering into negotiations with him.
"A professional shall only be free to conclude a contract with another club if his contract with his present club has expired or is due to expire within six months. Any breach of this provision shall be subject to appropriate sanctions."
What effect have the rules had in NI?
The rules surrounding pre-contract agreements may have helped precipitate the transfers of former Larne players Levi Ives and Joe Thomson, plus ex-Cliftonville midfielder Ronan Doherty in recent weeks.
Ives and Doherty were both understood to have agreed pre-contract terms with Coleraine but ultimately deals were made to enable the players to move in January, with transfer fees reportedly involved.
A similar scenario led to Thomson's switch to Glentoran just two days after he played for Larne against his future club in the County Antrim Shield final and almost scored the winning goal.
Joel Cooper has signed a pre-contract deal to move to Coleraine on the expiry of his current deal with Linfield and while the Bannsiders appear understandably keen to add the forward to their squad this month, the Blues have so far resisted their overtures and manager David Healy has indicated that he will not imminently be leaving Windsor Park for Ballycastle Road.
What the managers say
Glentoran manager Declan Devine talking to BBC Sport NI: "It's a strange one for me because I've never experienced it before. In the leagues I've previously worked in there were no letters going in for players.
"But you have to trust your players. It is a bit strange but also you have to keep planning for the future. That's just the nature of the game here in Northern Ireland."
Larne boss Gary Haveron: "It's far from ideal. Other leagues have restrictions on that and they have their reasons for doing that. It's maybe something we want to look into.
"[With players facing clubs they have agreed to join in the summer], there's the whole thing of 'do they want to play', 'have they the right mindset, the right mentality going into the game'."
The pundit's view
Former Carrick Rangers manager Stuart King paid tribute to the professionalism of players potentially involved in pre-contract deals in Northern Ireland but said the present situation did not sit easy with him.
"As a previous manager I would not like having a player [in my squad] knowing that he is not going to be there the following year," King told Sportsound on Saturday.
"I understand that there are certain examples, such as Joel Cooper at Linfield, where he is too important to the team, that he has to stay because they're potentially going to win the league because of Joel Cooper.
"Joe Thomson nearly scored the winner in injury-time in the County Antrim Shield final for Larne against Glentoran. Two days later he signs for Glentoran. He could have won the trophy for Larne in the last minute of the game.
"It doesn't sit right. It's uncomfortable for managers and staff. It's uncomfortable for players and most importantly it's really uncomfortable for the actual player involved."