If you carry a digitial camera (of a size that can be misplaced) on The Fells; save a file on any memory cards that you will use, name it 'camera owner information'; list your contact details within the file. I've made a jpg file for each card I carry, always keeping the file on the card.
That is kind of like the old film camera technique of yor first photograph being a card containing your details. Never done it myself but it does make sense. More so now that the memory cards allow a greater number of images to be stored hence being potentially a greater loss.
If anyone gives blood they get given a card with their name, blood group and a unique reference number. I always wondered if the police could use that to formally identify you. I mean if you are in a mess and can't identify yourself due to injuries or death then they would be able to confirm your blood group matches the card then contact the NBS to find your home address on their records. If they are not available to the poolice then I'd imagine they are linked somehow to your medical records, perhaps I'm wrong (would like to know if anyone has any idea). At least there is the full name on the card which I'm sure the police could use to identify you. They can with my name as there are not many people with my surname and very few indeed with the first and middle name too. whatever I do I always have my blood donor card with me and often my house keys with a keyring with my blood group on it.
On your phone always have a duplicate copy of your next of kin phone, email and messenger details on it but with the letters ICE in front of them. It has been widely known that ICE identifies your emergency contact. it means "In Case of Emergency". My additional tip is to have a second, back up contact in case they can't get hold of the first one.
Another tip is if you are able to leave your mobille phone on when out walking. If you do go missing for whatever reason it is supposed to be possible to use base stations to triangulate your location if you can get a signal. Failing that it records the last location you were when the phone connected, either by being turned on or off. Or at least that is what I've heard. Anything that can help reduce the area needing to be searched is an advantage. It also means you have to keep your phone charged.