All illegal drugs are classified, and next Thursday, January 29, cannabis moves from Class B to become a Class C drug, which will signal a change in the way the police will deal with adults caught in possession of small amounts of the drug for their own personal use.
But police officers stress that possession of cannabis will remain a criminal offence, and those who choose to flout the law by openly smoking cannabis in public will still face arrest, as will those who use the drug in places where children are likely to be.
Julie Muckle, Dyfed-Powys Police substance misuse officer, said: "Some people seem to be under the misconception that cannabis is being legalised - it isn't. It is being reclassified, which means is that in some circumstances, people found in possession of small amounts of the drug will not be arrested, but their cannabis will be confiscated.
"But if the same person is caught repeatedly - which can simply mean more than once - they will be arrested too."
Julie added: "Police officers have been asked to use their discretion and only consider making an arrest in these aggravated situations. But this applies only to adults - anyone aged 17 or under found in possession will still be arrested whatever the circumstances.
"I would also remind the public that cannabis remains a harmful substance and moving it from Class B to Class C doesn't mean that it is not as harmful as we thought. The risks associated with using it are not going to change - remember that its quality and strength can vary a great deal."