two weeks of a trial period players' names are obfuscated; match reports use the convention "A Trialist" to refer to such players in lieu of using their real names. Rugby league Player loans occur in rugby league for similar reasons to soccer. In the United Kingdom the Rugby Football League (RFL) stipulate that loans must last for at least 28 days. There is no bar against a player playing for the loan club against the parent club unless this has been specified in the loan agreement. In Australia the National Rugby League (NRL) does not normally allow loans due to the feeder club arrangement but the Covid-19 pandemic forced a review of the situation and in 2020 loans were allowed. Guest appearances In the First World War the RFL relaxed player registration rules to allow players to play for clubs close to their military base or workplace. Confusion could arise; in 1917 Billy Batten was working near to Dewsbury so Dewsbury selected him to play against his registered club, Hull FC. Hull had also selected Batten to play in the same game. On this occasion Batten chose to play for Dewsbury. During the Second World War the RFL allowed players to play as guests for another club on a match by match basis as long as the owning club agreed to the appearance. The system also allowed players whose club had suspended operations to play while still being registered to the original club Clubs made full use of the guest system; in the 1940–41 Championship final between Wigan and Bradford, Wigan featured guest players from Liverpool Stanley, Salford and Hull Kingston Rovers while Bradford included guests from Salford and Leeds. See also Free transfer Rugby League Dual registration References Terminology used in multiple sports Association football terminology Rugby league terminology Rugby union terminology Loans Sports labor relations