Best way to explain it is via an example.
An U/14 is with a club with no U/14 team. But there is an U/15 and/or an U/16 team. As he can play U/15 and U/16 it is considered that his club has a team for him. You cannot move simply because your club has no team at your specific age group.
Now if an U/14 is a member of a club with no team between that and minor he can be transferred at any time to another club as long as he has not played for his club in the current competition year. If he has then he's in limbo until the end of the year when he can request a transfer. This particular instance is unsatisfactory as a lad could play a couple of games and then see the team fold and have no outlet for a year but them's the rules.