Each cylinder will have a serial number and related valve/cylinder test certificate held by the owner to help maintain customer safety. In the past Calor and most others have relied upon trust worthy folk to continue returning for refills or simply bring back the empty thus minimizing "rogue cylinders" turning up.
Nowadays Calor will often require a fully refundable deposit (29.99) from non industrial customers and if you retain the paperwork will return your deposit in full.
Nowadays Calor will often require a fully refundable deposit (29.99) from non industrial customers and if you retain the paperwork will return your deposit in full.