There was a time not so very long ago when the judges got the impression, or so they said, that people were being far too keen to rush off to court and sue each other, with the result that the system was getting clogged up with lots of disputes that, in their opinion, could have been resolved in another way, and perhaps even amicably.
As a result, the judges introduced what they call 'protocols'. A Protocol is just a list of suggestions or instructions as to what somebody really should do before they bring a dispute to court. They are designed to try to increase the possibility of disputes being resolved without having to go to court.
Protocols are not compulsory. Nobody has to follow them if they don't want to. But if somebody takes a case to court or defends a case at court that has been brought against them without having complied with the protocol beforehand, then they can expect to receive a bit of a telling off from the judge. They might also be penalised with having to pay costs that they might not otherwise be lumbered with had they complied with the Protocol.
Not all sorts of cases have a Protocol that applies to them. In those circumstances there is what is called a Practice Direction, that simply says that you should try and behave in such a way as you would have done if there had been a Protocol, the essence of which is to try and resolve it amicably if at all possible.