Roger Hayter wrote:
The difference between passing an exam so that you can register a
callsign in order to obtain government permission to transmit and the
licence scheme in most other countries is much too subtle for me. What
is the difference? If transmitting without a callsign remains illegal,
this looks remarkably like a transmitting licence.

The difference as felt by some amateurs is that a license (is perceived to)
gives some rights, where a registration is just a system to know who
to contact when there is a problem with a certain amateur's transmissions,
more or less like a telephone number.