In the days before extensive coaching networks, you could always advertise for new players. That’s what the Swans did in 1923 and here’s an ad the club placed in the Athletic News, a paper with close ties to the Football League, on 14 May 1923.
In this era, clubs retained a player’s registration even if their contract had expired and they were no longer being paid. The ad thus asks about the transfer fee a player’s previous club might expect. In practice, not many clubs did retain players’ registrations and demand fees for players they were not paying. If word got around, that a club made it difficult for any player to move on after his contract expired, then finding new players might be difficult.