| M CATEGORY (FINAL PRETREATMENT) | Data Element | 
        | M CATEGORY (INTEGRATED STAGE) | Data Element | 
        | M CATEGORY (PATHOLOGICAL) | Data Element | 
        | M CATEGORY EXTENDED (PATHOLOGICAL) (Retired) | Data Element | 
        | MACHINE | Class | 
        | MACHINE IDENTIFIER | Attribute | 
        | MACHINE IDENTIFIER | Data Element | 
        | MACHINE NAME (Retired) | Attribute | 
        | MACHINE TYPE (Retired) | Attribute | 
        | MACROSCOPIC EXTRAGLANDULAR EXTENSION INDICATION CODE | Attribute | 
        | MACROSCOPIC EXTRAGLANDULAR EXTENSION INDICATION CODE | Data Element | 
        | MAIN SPECIALTY | Class | 
        | Main Specialty and Treatment Function Codes Table | Supporting Information | 
        | MAIN SPECIALTY CATEGORY CODE FOR BED AVAILABILITY AND OCCUPANCY (Retired) | Attribute | 
        | MAIN SPECIALTY CATEGORY CODE FOR BED AVAILABILITY AND OCCUPANCY (Retired) | Data Element | 
        | MAIN SPECIALTY CODE | Attribute | 
        | MAIN SPECIALTY CODE (Retired) | Data Element | 
        | MAIN SPECIALTY CODE (AUGMENTED CARE PERIOD) (Retired) | Data Element | 
        | MAIN SPECIALTY CODE (MENTAL HEALTH) | Data Element | 
        | MALIGNANCY TREATMENT INDICATOR (HIV) | Data Element | 
        | MALIGNANCY TREATMENT INDICATOR FOR HIV | Attribute | 
        | MALIGNANT ABNORMALITY | Class | 
        | MALIGNANT PLEURAL EFFUSION INDICATOR | Attribute | 
        | MALIGNANT PLEURAL EFFUSION INDICATOR | Data Element | 
        | Mammogram | NHS Business Definition | 
        | MAMMOGRAM RESULT CODE (Retired) | Attribute | 
        | MAMMOGRAM RESULT CODE (Retired) | Data Element | 
        | MANIFEST PSYCHOSIS DATE | Data Element | 
        | Mantoux Test (Retired) | NHS Business Definition | 
        | MANTOUX TESTS PERFORMED TOTAL (TUBERCULOSIS) (Retired) | Data Element | 
        | MANUFACTURERS NAME (DIALYSER) (Retired) | Data Element | 
        | MARGIN INVOLVED INDICATION CODE | Attribute | 
        | MARGIN INVOLVED INDICATION CODE (CIRCUMFERENTIAL MARGIN) | Data Element | 
        | MARGIN INVOLVED INDICATION CODE (COLORECTAL PROXIMAL OR DISTAL RESECTION MARGIN) | Data Element | 
        | MARGIN INVOLVED INDICATION CODE (PROXIMAL OR DISTAL RESECTION MARGIN) | Data Element | 
        | MARGIN INVOLVED INDICATION CODE FOR COLORECTAL | Attribute | 
        | MARITAL STATUS (Retired) | Data Element | 
        | MARKER LYMPH NODE RESULT (Retired) | Attribute | 
        | MARKER LYMPH NODE RESULT (Retired) | Data Element | 
        | MARKER RESPONSE STATUS (Retired) | Attribute | 
        | MARKER RESPONSE STATUS (Retired) | Data Element | 
        | Market Forces Factor | Supporting Information | 
        | Maternal Critical Incident Date and Time (Retired) | NHS Business Definition | 
        | MATERNAL CRITICAL INCIDENT DATE TIME (Retired) | Data Element | 
        | MATERNAL CRITICAL INCIDENT INDICATOR | Attribute | 
        | MATERNAL CRITICAL INCIDENT INDICATOR | Data Element | 
        | MATERNAL CRITICAL INCIDENT TYPE (Retired) | Attribute | 
        | MATERNAL CRITICAL INCIDENT TYPE (Retired) | Data Element | 
        | MATERNAL HEP B STATUS (Retired) | Attribute | 
        | MATERNAL RUBELLA STATUS (Retired) | Attribute | 
        | MATERNITY CARE PLAN DATE | Data Element | 
        | MATERNITY CARE PLAN TYPE | Data Element | 
        | MATERNITY CARE SETTING | Attribute | 
        | MATERNITY CARE SETTING (ACTUAL PLACE OF BIRTH) | Data Element | 
        | MATERNITY CARE SETTING (AT START OF INTRAPARTUM CARE) | Data Element | 
        | MATERNITY CARE SETTING (OF PLANNED DELIVERY) | Data Element | 
        | MATERNITY COMPLICATING DIAGNOSIS INDICATOR | Attribute | 
        | MATERNITY COMPLICATING DIAGNOSIS INDICATOR | Data Element | 
        | MATERNITY COMPLICATING MEDICAL DIAGNOSIS | Attribute | 
        | MATERNITY COMPLICATING MEDICAL DIAGNOSIS TYPE (MOTHER AT BOOKING) (Retired) | Data Element | 
        | MATERNITY COMPLICATING MEDICAL DIAGNOSIS TYPE (NATIONAL NEONATAL DATA SET) | Data Element | 
        | MATERNITY COMPLICATING SEXUALLY TRANSMITTED INFECTION DIAGNOSIS (MOTHER AT BOOKING) (Retired) | Data Element | 
        | Maternity Domiciliary Visit | NHS Business Definition | 
        | Maternity Episode | NHS Business Definition | 
        | MATERNITY FAMILY HISTORY DIAGNOSIS TYPE (Retired) | Attribute | 
        | MATERNITY FAMILY HISTORY DIAGNOSIS TYPE (AT BOOKING) (Retired) | Data Element | 
        | MATERNITY MEDICAL DIAGNOSIS TYPE | Attribute | 
        | MATERNITY MEDICAL DIAGNOSIS TYPE (CURRENT PREGNANCY) | Data Element | 
        | Maternity Medical Service (Retired) | NHS Business Definition | 
        | MATERNITY MEDICAL SERVICE TYPE (Retired) | Attribute | 
        | MATERNITY OBSTETRIC DIAGNOSIS TYPE (CURRENT PREGNANCY) | Data Element | 
        | MATERNITY PERSONALISED CARE PLAN INDICATOR | Attribute | 
        | MATERNITY PERSONALISED CARE PLAN INDICATOR | Data Element | 
        | MATERNITY PREVIOUS COMPLICATING OBSTETRIC DIAGNOSIS TYPE (MOTHER AT BOOKING) (Retired) | Data Element | 
        | MATERNITY SCREENING TESTS BOOKLET GIVEN DATE (Retired) | Data Element | 
        | Maternity Service | NHS Business Definition | 
        | Maternity Services Data Set | Data Set | 
        | Maternity Services Data Set Constraints | XML Schema Constraint | 
        | MATERNITY SEXUALLY TRANSMITTED INFECTION DIAGNOSIS (CURRENT PREGNANCY) (Retired) | Data Element | 
        | MATERNITY SUBMISSION RECORD COUNT (Retired) | Data Element | 
        | MATERNITY VISIT CALL REASON (Retired) | Attribute | 
        | MAXIMUM DEPTH OF INVASION | Attribute | 
        | MAXIMUM DEPTH OF INVASION | Data Element | 
        | MAXIMUM WAIT FOR DAY CASE ADMISSION (Retired) | Attribute | 
        | MAXIMUM WAIT FOR ORDINARY ADMISSION (Retired) | Attribute | 
        | MEAN ARTERIAL BLOOD PRESSURE (ON ADMISSION TO NEONATAL CRITICAL CARE) | Data Element | 
        | MEASURED 24HR CREATININE CLEARANCE (Retired) | Data Element | 
        | MEASURED CREATININE CLEARANCE (Retired) | Data Element | 
        | MEASURED GLOMERULAR FILTRATION RATE (Retired) | Data Element | 
        | MEASURED GLOMERULAR FILTRATION RATE TYPE CODE (Retired) | Attribute | 
        | MEASURED GLOMERULAR FILTRATION RATE TYPE CODE (Retired) | Data Element | 
        | MEASURED OBSERVATION VALUE (Retired) | Attribute | 
        | MEASURED PERSON OBSERVATION (Retired) | Class | 
        | MEASURED PERSON OBSERVATION TYPE (Retired) | Class | 
        | MEASURED PERSON OBSERVATION TYPE CODE (Retired) | Attribute | 
        | Measured Referral to Treatment Period | NHS Business Definition | 
        | MEASUREMENT VALUE TYPE (Retired) | Class | 
        | MEASUREMENT VALUE TYPE CODE (Retired) | Attribute | 
        | MECHANICAL THROMBOPROPHYLAXIS REGIME TYPE (JOINT REPLACEMENT) | Data Element | 
        | MECHANICAL THROMBOPROPHYLAXIS REGIME TYPE FOR JOINT REPLACEMENT | Attribute | 
        | MECONIUM PRESENT IN LIQUOR INDICATOR | Attribute | 
        | MECONIUM PRESENT IN LIQUOR INDICATOR | Data Element | 
        | MEDIASTINAL SAMPLING INDICATOR | Attribute | 
        | MEDIASTINAL SAMPLING INDICATOR | Data Element | 
        | MEDICAL AND DENTAL POST SPECIALTY GROUP (Retired) | Attribute | 
        | MEDICAL DEVICE | Class | 
        | MEDICAL DEVICE IDENTIFIER | Attribute | 
        | MEDICAL DEVICE MANUFACTURER | Attribute | 
        | MEDICAL DEVICE MANUFACTURER (HIGH COST TARIFF EXCLUDED DEVICE) | Data Element | 
        | MEDICAL DEVICE NAME | Attribute | 
        | MEDICAL DEVICE NAME (HIGH COST TARIFF EXCLUDED DEVICE) | Data Element | 
        | MEDICAL DEVICE PROCUREMENT ROUTE | Attribute | 
        | MEDICAL DEVICE PROCUREMENT ROUTE (HIGH COST TARIFF EXCLUDED DEVICE) | Data Element | 
        | MEDICAL DEVICE QUANTITY | Attribute | 
        | MEDICAL DEVICE QUANTITY (HIGH COST TARIFF EXCLUDED DEVICE) | Data Element | 
        | MEDICAL DEVICE SERIAL NUMBER | Attribute | 
        | MEDICAL DEVICE SERIAL NUMBER (HIGH COST TARIFF EXCLUDED DEVICE) | Data Element | 
        | MEDICAL DEVICE SIZE | Attribute | 
        | MEDICAL DEVICE SIZE (HIGH COST TARIFF EXCLUDED DEVICE) | Data Element | 
        | MEDICAL INDUCTION OF LABOUR AGENT (Retired) | Attribute | 
        | MEDICAL INDUCTION OF LABOUR METHOD (Retired) | Data Element | 
        | MEDICAL STAFF TYPE SEEING PATIENT | Attribute | 
        | MEDICAL STAFF TYPE SEEING PATIENT | Data Element | 
        | MEDICATION GIVEN DURING LABOUR (SNOMED CT DM+D) | Data Element | 
        | MEDICATION GIVEN DURING NEONATAL CRITICAL CARE DAILY CARE DATE (SNOMED CT DM+D) | Data Element | 
        | Medicines and Healthcare Products Regulatory Agency | NHS Business Definition | 
        | MEMBER OF SPECIALIST MULTIDISCIPLINARY TEAM INDICATOR | Attribute | 
        | MEMBER OF SPECIALIST MULTIDISCIPLINARY TEAM INDICATOR | Data Element | 
        | MENOPAUSAL STATUS | Class | 
        | MENOPAUSAL STATUS | Attribute | 
        | MENOPAUSAL STATUS (AT DIAGNOSIS) | Data Element | 
        | MENSTRUAL STATUS (Retired) | Attribute | 
        | MENSTRUAL STATUS (Retired) | Data Element | 
        | MENTAL CATEGORY | Attribute | 
        | MENTAL CATEGORY (Retired) | Data Element | 
        | Mental Health Absence Without Leave | NHS Business Definition | 
        | MENTAL HEALTH ABSENCE WITHOUT LEAVE END REASON | Attribute | 
        | MENTAL HEALTH ABSENCE WITHOUT LEAVE END REASON | Data Element | 
        | MENTAL HEALTH ABSOLUTE DISCHARGE RESPONSIBILITY | Attribute | 
        | MENTAL HEALTH ABSOLUTE DISCHARGE RESPONSIBILITY | Data Element | 
        | MENTAL HEALTH ACT 2007 MENTAL CATEGORY | Attribute | 
        | MENTAL HEALTH ACT 2007 MENTAL CATEGORY | Data Element | 
        | Mental Health Act Legal Status (Retired) | NHS Business Definition | 
        | MENTAL HEALTH ACT LEGAL STATUS CLASSIFICATION | Class | 
        | Mental Health Act Legal Status Classification Assignment Period | NHS Business Definition | 
        | MENTAL HEALTH ACT LEGAL STATUS CLASSIFICATION ASSIGNMENT PERIOD END REASON | Attribute | 
        | MENTAL HEALTH ACT LEGAL STATUS CLASSIFICATION ASSIGNMENT PERIOD END REASON | Data Element | 
        | MENTAL HEALTH ACT LEGAL STATUS CLASSIFICATION ASSIGNMENT PERIOD IDENTIFIER | Data Element | 
        | MENTAL HEALTH ACT LEGAL STATUS CLASSIFICATION ASSIGNMENT PERIOD START REASON | Attribute | 
        | MENTAL HEALTH ACT LEGAL STATUS CLASSIFICATION ASSIGNMENT PERIOD START REASON | Data Element | 
        | MENTAL HEALTH ACT LEGAL STATUS CLASSIFICATION CODE | Attribute | 
        | MENTAL HEALTH ACT LEGAL STATUS CLASSIFICATION CODE | Data Element | 
        | MENTAL HEALTH ACT LEGAL STATUS CLASSIFICATION CODE (AT CENSUS DATE) | Data Element | 
        | MENTAL HEALTH ACT LEGAL STATUS CLASSIFICATION CODE (ON ADMISSION) | Data Element | 
        | Mental Health Act Table (Retired) | Supporting Information | 
        | MENTAL HEALTH ADMITTED PATIENT CLASSIFICATION | Attribute | 
        | MENTAL HEALTH ADMITTED PATIENT CLASSIFICATION | Data Element | 
        | Mental Health and Learning Disabilities Data Set (Retired) | Data Set | 
        | MENTAL HEALTH CARE AND LEGAL STATUS HISTORY (Retired) | Data Element | 
        | Mental Health Care Assessment Date (Retired) | NHS Business Definition | 
        | Mental Health Care Cluster Assignment Period (Retired) | NHS Business Definition | 
        | MENTAL HEALTH CARE CLUSTER END REASON (Retired) | Attribute | 
        | MENTAL HEALTH CARE CLUSTER END REASON (Retired) | Data Element | 
        | Mental Health Care Cluster Super Class | Supporting Information | 
        | MENTAL HEALTH CARE CLUSTER SUPER CLASS CODE | Attribute | 
        | MENTAL HEALTH CARE CLUSTER SUPER CLASS CODE | Data Element | 
        | MENTAL HEALTH CARE CONTACT IDENTIFIER (Retired) | Data Element | 
        | Mental Health Care Coordinator | NHS Business Definition | 
        | Mental Health Care Coordinator Assignment Period | NHS Business Definition | 
        | Mental Health Care Plan | NHS Business Definition | 
        | Mental Health Care Professional Episode (Acute Home-based) (Retired) | NHS Business Definition | 
        | Mental Health Care Spell (Retired) | NHS Business Definition | 
        | MENTAL HEALTH CARE SPELL END CODE (Retired) | Attribute | 
        | MENTAL HEALTH CARE SPELL END CODE (Retired) | Data Element | 
        | Mental Health Care Spell Suspension (Retired) | NHS Business Definition | 
        | Mental Health Care Team Member (Retired) | NHS Business Definition | 
        | MENTAL HEALTH CARE TEAM TYPE (AT END OF REPORTING PERIOD) (Retired) | Data Element | 
        | Mental Health Care Without Patient Consent (Retired) | NHS Business Definition | 
        | MENTAL HEALTH CONDITIONAL DISCHARGE END REASON | Attribute | 
        | MENTAL HEALTH CONDITIONAL DISCHARGE END REASON | Data Element | 
        | Mental Health Conditional Discharge Period | NHS Business Definition | 
        | Mental Health Crisis Plan | NHS Business Definition | 
        | MENTAL HEALTH CRISIS PLAN CREATION DATE (Retired) | Data Element | 
        | Mental Health Crisis Plan Creation Date (Retired) | NHS Business Definition | 
        | MENTAL HEALTH CRISIS PLAN LAST UPDATED DATE (Retired) | Data Element | 
        | Mental Health Crisis Plan Last Updated Date (Retired) | NHS Business Definition | 
        | MENTAL HEALTH DELAYED DISCHARGE ATTRIBUTABLE TO INDICATION CODE | Attribute | 
        | MENTAL HEALTH DELAYED DISCHARGE ATTRIBUTABLE TO INDICATION CODE | Data Element | 
        | Mental Health Delayed Discharge Period | NHS Business Definition | 
        | MENTAL HEALTH DELAYED DISCHARGE REASON | Attribute | 
        | MENTAL HEALTH DELAYED DISCHARGE REASON | Data Element | 
        | MENTAL HEALTH INTERVENTION CODE (Retired) | Attribute | 
        | Mental Health Leave of Absence | NHS Business Definition | 
        | MENTAL HEALTH LEAVE OF ABSENCE END REASON | Attribute | 
        | MENTAL HEALTH LEAVE OF ABSENCE END REASON | Data Element | 
        | Mental Health Minimum Data Set (Retired) | Data Set | 
        | Mental Health Minimum Data Set (Version 4-0) (Retired) | Data Set | 
        | Mental Health Minimum Data Set (Version 4-1) (Retired) | Data Set | 
        | Mental Health NHS Day Care Episode (Retired) | NHS Business Definition | 
        | Mental Health Nursing | Supporting Information | 
        | MENTAL HEALTH PREDICTION AND DETECTION INDICATOR | Attribute | 
        | MENTAL HEALTH PREDICTION AND DETECTION INDICATOR (AT ANTENATAL BOOKING) | Data Element | 
        | Mental Health Responsible Clinician | NHS Business Definition | 
        | Mental Health Responsible Clinician Assignment Period | NHS Business Definition | 
        | MENTAL HEALTH RESPONSIBLE CLINICIAN PROFESSION (Retired) | Attribute | 
        | MENTAL HEALTH RESPONSIBLE CLINICIAN PROFESSION (Retired) | Data Element | 
        | Mental Health Service | NHS Business Definition | 
        | Mental Health Services Data Set | Data Set | 
        | Mental Health Services Data Set Constraints | XML Schema Constraint | 
        | Mental Health Treatment (Retired) | NHS Business Definition | 
        | Mental Health Trial Leave | NHS Business Definition | 
        | META ACTIVITY | Class | 
        | META ACTIVITY IDENTIFIER | Attribute | 
        | META ACTIVITY QUALIFIER | Class | 
        | META ACTIVITY QUALIFIER IDENTIFIER | Attribute | 
        | META ACTIVITY SITE | Class | 
        | META ACTIVITY STATE ATTAINED DATE | Attribute | 
        | META ACTIVITY STATE ATTAINED TIME | Attribute | 
        | META ACTIVITY STATE ATTAINED TYPE | Attribute | 
        | META AGENT | Class | 
        | META AGENT IDENTIFIER | Attribute | 
        | META CARE ACTIVITY | Class | 
        | META CARE ACTIVITY CONTEXT | Class | 
        | META CARE ACTIVITY DIRECT | Class | 
        | META CARE ACTIVITY IN CONTEXT | Class | 
        | META CARE PATHWAY USE | Class | 
        | META CARE PROFESSIONAL | Class | 
        | META CARE SPELL | Class | 
        | META CARE SPELL IDENTIFIER | Attribute | 
        | META CARER FOR PERSON | Class | 
        | META CHANGE ACTIVITY STATE | Class | 
        | META CONTRACT IDENTIFIER | Attribute | 
        | META CONTRACTOR | Class | 
        | META CONTRACTUAL RELATIONSHIP | Class | 
        | META DIRECT ACTIVITY QUALIFIER | Class | 
        | META DIRECT PERSON PROPERTY QUALIFIER | Class | 
        | META EMPLOYEE | Class | 
        | META HEALTH AND SOCIAL CARE ISSUE | Class | 
        | META INDIRECT ACTIVITY QUALIFIER | Class | 
        | META INDIRECT PERSON PROPERTY QUALIFIER | Class | 
        | META ORGANISATION | Class | 
        | META ORGANISATION IDENTIFIER | Attribute | 
        | META ORGANISATION SITE | Class | 
        | META ORGANISATION SITE IDENTIFIER | Attribute | 
        | META ORGANISATION STRUCTURE | Class | 
        | META ORGANISATION TYPE | Attribute | 
        | META PATIENT | Class | 
        | META PERSON | Class | 
        | META PERSON IDENTIFIER | Attribute | 
        | META PERSON OBSERVATION | Class | 
        | META PERSON PROPERTY | Class | 
        | META PERSON PROPERTY IDENTIFIER | Attribute | 
        | META PERSON PROPERTY QUALIFIER | Class | 
        | META PERSON PROPERTY QUALIFIER IDENTIFIER | Attribute | 
        | META PERSON RELATIONSHIP | Class | 
        | META PERSON ROLE IN ORGANISATION | Class | 
        | META PLACE | Class | 
        | META POST | Class | 
        | META POST IDENTIFIER | Attribute | 
        | META POST TYPE | Attribute | 
        | META RESOURCE HELD | Class | 
        | META RESOURCE USAGE | Class | 
        | META ROLE IN ACTIVITY | Class | 
        | META SERVICE OFFERED | Class | 
        | META SERVICE OFFERED TYPE | Attribute | 
        | META SESSION | Class | 
        | META SESSION START TIME | Attribute | 
        | META TIME SLOT | Class | 
        | METABOLIC SCREENING (Retired) | Attribute | 
        | Metadata Files (Retired) | Supporting Information | 
        | METASTASIS EXTENT CODE | Attribute | 
        | METASTASIS EXTENT CODE | Data Element | 
        | METASTATIC SITE | Attribute | 
        | METASTATIC SITE (AT DIAGNOSIS) | Data Element | 
        | METASTATIC STATUS | Attribute | 
        | METASTATIC STATUS | Data Element | 
        | METHOD OF COMMUNICATION (END OF CANCER FASTER DIAGNOSIS PATHWAY) | Data Element | 
        | METHOD OF COMMUNICATION FOR END OF CANCER FASTER DIAGNOSIS PATHWAY | Attribute | 
        | METHOD OF ESTIMATED DATE OF DELIVERY | Attribute | 
        | METHOD OF ESTIMATED DATE OF DELIVERY (AGREED) | Data Element | 
        | Metropolitan County | NHS Business Definition | 
        | Metropolitan District | NHS Business Definition | 
        | MHC WITHOUT PATIENT CONSENT IN REPORTING PERIOD (Retired) | Data Element | 
        | MHCS SUSPENSION REASON (AT END OF REPORTING PERIOD) (Retired) | Data Element | 
        | MHMDS CONTROL NUMBER (Retired) | Data Element | 
        | MHMDS DATE CREATED (Retired) | Data Element | 
        | MHMDS DESTINATION IDENTIFICATION (Retired) | Data Element | 
        | MHMDS HEADER RECORD IDENTIFIER (Retired) | Data Element | 
        | MHMDS INTERFACE GATEWAY SERVICE TRANSLATION REFERENCE (Retired) | Data Element | 
        | MHMDS LOCAL PATIENT IDENTIFIER (Retired) | Data Element | 
        | MHMDS RECORD COUNT (Retired) | Data Element | 
        | MHMDS RECORD IDENTIFIER (Retired) | Data Element | 
        | MHMDS RECORD NUMBER (Retired) | Data Element | 
        | MHMDS SOURCE IDENTIFICATION (Retired) | Data Element | 
        | MHMDS TEST INDICATOR (Retired) | Data Element | 
        | MHMDS TIME CREATED (Retired) | Data Element | 
        | MHMDS TRAILER RECORD IDENTIFIER (Retired) | Data Element | 
        | MHMDS TRANSLATION REFERENCE (Retired) | Data Element | 
        | MICROSATELLITE INSTABILITY TESTING RESULT | Attribute | 
        | MICROSATELLITE INSTABILITY TESTING RESULT | Data Element | 
        | MICROSATELLITE OR IN-TRANSIT METASTASIS INDICATION CODE | Attribute | 
        | MICROSATELLITE OR IN-TRANSIT METASTASIS INDICATION CODE | Data Element | 
        | MICROSCOPIC INVOLVEMENT INDICATION CODE (FALLOPIAN TUBE) | Data Element | 
        | MICROSCOPIC INVOLVEMENT INDICATION CODE (OVARIAN) | Data Element | 
        | MICROSCOPIC INVOLVEMENT INDICATION CODE (UTERINE SEROSA) | Data Element | 
        | MICROSCOPIC INVOLVEMENT INDICATION CODE FOR FALLOPIAN TUBE OR OVARIAN CANCER | Attribute | 
        | MICROSCOPIC INVOLVEMENT INDICATION CODE FOR UTERINE SEROSA | Attribute | 
        | MICROSCOPIC INVOLVEMENT INDICATOR (CERVICAL STROMA) | Data Element | 
        | MICROSCOPIC INVOLVEMENT INDICATOR (CERVICAL SURFACE OR GLANDS) (Retired) | Data Element | 
        | MICROSCOPIC INVOLVEMENT INDICATOR (PARAMETRIUM) | Data Element | 
        | MICROSCOPIC INVOLVEMENT INDICATOR (VAGINAL) | Data Element | 
        | MICROSCOPIC INVOLVEMENT INDICATOR FOR PARAMETRIUM OR CERVICAL STROMA | Attribute | 
        | MICROSCOPIC INVOLVEMENT INDICATOR FOR VAGINAL | Attribute | 
        | Microwave Ablation | NHS Business Definition | 
        | MID ARM CIRCUMFERENCE (Retired) | Data Element | 
        | Mid Arm Circumference | NHS Business Definition | 
        | Middle Layer Super Output Area | NHS Business Definition | 
        | MIDWIFE | Class | 
        | Midwife Clinic | NHS Business Definition | 
        | Midwife Episode | NHS Business Definition | 
        | MIDWIFE EPISODE END REASON (Retired) | Attribute | 
        | MIDWIFERY ADMISSION RIGHT (Retired) | Attribute | 
        | MIDWIFERY UNIT TYPE (Retired) | Attribute | 
        | MINIMALLY INVASIVE OESOPHAGECTOMY SURGICAL APPROACH TYPE | Attribute | 
        | MINIMALLY INVASIVE OESOPHAGECTOMY SURGICAL APPROACH TYPE | Data Element | 
        | MINIMALLY INVASIVE SURGERY INDICATOR (JOINT REPLACEMENT) | Data Element | 
        | MINIMALLY INVASIVE SURGERY INDICATOR FOR JOINT REPLACEMENT | Attribute | 
        | Minor Surgery Procedure (Retired) | NHS Business Definition | 
        | MINOR SURGERY TYPE (Retired) | Attribute | 
        | Miscarriage Date (Retired) | NHS Business Definition | 
        | MITOTIC RATE (SARCOMA) | Data Element | 
        | MITOTIC RATE (SKIN) | Data Element | 
        | MIXED PHENOTYPE ACUTE LEUKAEMIA SYMPTOMS | Attribute | 
        | MIXED PHENOTYPE ACUTE LEUKAEMIA SYMPTOMS (AT DIAGNOSIS) | Data Element | 
        | Mixed-Sex Accommodation Data Set (Retired) | Data Set | 
        | MLH1 IMMUNOHISTOCHEMISTRY NUCLEAR EXPRESSION INTACT INDICATION CODE | Data Element | 
        | MODE OF DELIVERY | Attribute | 
        | MODE OF DELIVERY | Data Element | 
        | MODIFIED DUKES STAGE (Retired) | Attribute | 
        | MODIFIED DUKES STAGE (Retired) | Data Element | 
        | MODIFIED DUKES STAGE DATE (Retired) | Data Element | 
        | Modified Dukes Stage Date (Retired) | NHS Business Definition | 
        | MOLECULAR DIAGNOSTIC CODE | Attribute | 
        | MOLECULAR DIAGNOSTIC CODE | Data Element | 
        | Monitor (Retired) | NHS Business Definition | 
        | MONITORING INTENT (Retired) | Attribute | 
        | MONITORING INTENT (Retired) | Data Element | 
        | MONTHLY EXTRACT TOTAL COST (PATIENT LEVEL INFORMATION COSTING) | Data Element | 
        | Mood and Feelings Questionnaire (Retired) | NHS Business Definition | 
        | MORBIDITY CODE (Retired) | Attribute | 
        | MORBIDITY CODE (CANCER SURGERY) (Retired) | Data Element | 
        | MORBIDITY CODE (CHEMOTHERAPY) (Retired) | Data Element | 
        | MORBIDITY CODE (COMBINATION) (Retired) | Data Element | 
        | MORBIDITY CODE (RADIOTHERAPY) (Retired) | Data Element | 
        | MORE THAN THREE RECTAL WASHOUTS RECEIVED INDICATOR | Attribute | 
        | MORE THAN THREE RECTAL WASHOUTS RECEIVED INDICATOR | Data Element | 
        | MORPHOLOGY (ICD-O AT START SYSTEMIC ANTI-CANCER THERAPY) | Data Element | 
        | MORPHOLOGY (ICD-O CANCER TRANSFORMATION ORIGINAL) | Data Element | 
        | MORPHOLOGY (ICD-O CANCER TRANSFORMATION) | Data Element | 
        | MORPHOLOGY (ICD-O DIAGNOSIS) | Data Element | 
        | MORPHOLOGY (SNOMED CANCER TRANSFORMATION ORIGINAL) | Data Element | 
        | MORPHOLOGY (SNOMED CANCER TRANSFORMATION) | Data Element | 
        | MORPHOLOGY (SNOMED CT) (Retired) | Data Element | 
        | MORPHOLOGY (SNOMED DIAGNOSIS) | Data Element | 
        | MORPHOLOGY (SNOMED PATHOLOGY) | Data Element | 
        | MOTHER ANTENATALLY BOOKED INDICATOR | Attribute | 
        | MOTHER ANTENATALLY BOOKED INDICATOR | Data Element | 
        | MOTHER CURRENT SMOKER AT BOOKING INDICATOR | Attribute | 
        | MOTHER CURRENT SMOKER AT BOOKING INDICATOR | Data Element | 
        | Mothers Sexual Health and Infectious Diseases Data Set (Retired) | Data Set | 
        | MRI Scan | NHS Business Definition | 
        | MRI ULTRASOUND FUSION GUIDED BIOPSY INDICATOR | Attribute | 
        | MRI ULTRASOUND FUSION GUIDED BIOPSY INDICATOR | Data Element | 
        | MSH2 IMMUNOHISTOCHEMISTRY NUCLEAR EXPRESSION INTACT INDICATION CODE | Data Element | 
        | MSH6 IMMUNOHISTOCHEMISTRY NUCLEAR EXPRESSION INTACT INDICATION CODE | Data Element | 
        | Multi-bed Bay (Retired) | NHS Business Definition | 
        | Multi-disciplinary Consultation (National Tariff Payment System) | NHS Business Definition | 
        | Multi-professional Consultation (National Tariff Payment System) | NHS Business Definition | 
        | MULTI-PROFESSIONAL OR MULTI-DISCIPLINARY INDICATION CODE | Attribute | 
        | MULTI-PROFESSIONAL OR MULTI-DISCIPLINARY INDICATION CODE (PAYMENT BY RESULTS) | Data Element | 
        | Multidisciplinary Team | NHS Business Definition | 
        | MULTIDISCIPLINARY TEAM CANCER CARE PLAN DISCUSSED INDICATOR (Retired) | Attribute | 
        | MULTIDISCIPLINARY TEAM CANCER CARE PLAN DISCUSSED INDICATOR (Retired) | Data Element | 
        | MULTIDISCIPLINARY TEAM DISCUSSION DATE (CANCER) | Data Element | 
        | Multidisciplinary Team Discussion Date (Cancer) | NHS Business Definition | 
        | Multidisciplinary Team Meeting | NHS Business Definition | 
        | MULTIDISCIPLINARY TEAM MEETING CANCER CARE PLAN DISCUSSION TYPE | Attribute | 
        | MULTIDISCIPLINARY TEAM MEETING CANCER CARE PLAN DISCUSSION TYPE | Data Element | 
        | MULTIDISCIPLINARY TEAM MEETING CANCER CARE PLAN NOT DISCUSSED INDICATION CODE | Attribute | 
        | MULTIDISCIPLINARY TEAM MEETING CANCER CARE PLAN NOT DISCUSSED INDICATION CODE | Data Element | 
        | MULTIDISCIPLINARY TEAM MEETING DATE (CANCER) | Data Element | 
        | Multidisciplinary Team Meeting Date (Cancer) | NHS Business Definition | 
        | MULTIDISCIPLINARY TEAM MEETING TYPE (CANCER) | Data Element | 
        | MULTIDISCIPLINARY TEAM MEETING TYPE COMMENT (CANCER) | Data Element | 
        | MULTIDISCIPLINARY TEAM MEETING TYPE FOR CANCER | Attribute | 
        | MULTIDISCIPLINARY TEAM RECOMMENDATION (NHS CONTINUING HEALTHCARE STANDARD) | Data Element | 
        | MULTIDISCIPLINARY TEAM RECOMMENDATION FOR NHS CONTINUING HEALTHCARE STANDARD | Attribute | 
        | MULTIFOCAL OR SYNCHRONOUS TUMOUR INDICATOR | Attribute | 
        | MULTIFOCAL OR SYNCHRONOUS TUMOUR INDICATOR | Data Element | 
        | MULTIFOCAL TUMOUR INDICATOR (BREAST) | Data Element | 
        | MULTIFOCAL TUMOUR INDICATOR FOR BREAST | Attribute | 
        | MULTIPARAMETRIC MRI SCAN INDICATOR | Attribute | 
        | MULTIPARAMETRIC MRI SCAN INDICATOR | Data Element | 
        | MURPHY ST JUDE STAGE | Attribute | 
        | MURPHY ST JUDE STAGE | Data Element | 
        | MURPHY ST JUDE STAGE DATE (Retired) | Data Element | 
        | Murphy St Jude Stage Date (Retired) | NHS Business Definition | 
        | MUSCLE TRANSFER INDICATOR (SHOULDER REPLACEMENT) | Data Element | 
        | MYCOPHENOLIC ACID TROUGH LEVEL (RECIPIENT) (Retired) | Data Element | 
        | MYELOMA INTERNATIONAL STAGING SYSTEM STAGE (Retired) | Attribute | 
        | MYELOMA INTERNATIONAL STAGING SYSTEM STAGE (Retired) | Data Element | 
        | MYELOMA INTERNATIONAL STAGING SYSTEM STAGE DATE (Retired) | Data Element | 
        | Myeloma International Staging System Stage Date (Retired) | NHS Business Definition | 
        | MYOMETRIAL INVASION IDENTIFICATION CODE | Attribute | 
        | MYOMETRIAL INVASION IDENTIFICATION CODE | Data Element |