In one of those strange coincidences I was actually looking at this today as part of my current job in the NHS where I work with GP Practices managing patient records. The reference document is JSP 950 Leaflet 1-2-11 dated 17 Dec 13. It states:
Defence Health Record on leaving
61. On discharge the patient is to be given a paper FMed 133 (Medical History on Release from HM Forces) that includes information on vaccinations, medicals and a summary of their healthcare. They are to be advised to take this form to their NHS General Practice on registering. On registering with an NHS practice there will be an automated request for the NHS PHR held at LaSCA. Copies of the DHR will be available to the NHS practice if they require them, following the guidance on the FMed 133.
A copy of the document is here:
https://www.whatdotheyknow.com/reque...V1%201%20U.pdf