I see above a link to the Ofcom FAQ. As usual this is a bit disingenous, where it states that they have not found any breach of the essential requirements of the EMC Regulations, what they fail to state is that in all the tests that have been conducted by independent test houses the peak level of emissions is >30dB above the EN55022 Class B limits, which is a strange definition of EMC compliant in my book.
Ofcom is a politically motivated body, and it doesn't want to rock the boat with the EU and brand PLT devices as illegal in the UK because that would affect european trade and the supply of "harmonised" goods.
The PLT regulation process via the CISPR committee has totally failed, it has not been possible to agree limits that simultaneously allow the PLT devices to work as desired and to meet accepted EMC limits that have been enforced for decades. This process is being restarted, but is likely to be gerrymandered by the European Commission to allow existing non-compliant devices to be sold.
EMC engineers are up in arms about this, if the approach being used were to be extended to other standards then you can forget ever having interoperating non-interfering RF-based systems ever again, ultimately sense might prevail but only after all our wide area systems had been crippled by wideband interference.
We can only hope that this sort of wired networking is out-evolved by other technologies and dies a natural death. Otherwise it's going to be a train wreck.