Update test-certificate_eu_schema.md

schemas/test-certificate_eu_schema.md

@@ -16,7 +16,7 @@ All EU Countries
 | 2 | EU Beneficiary Name         | Full name of the individual                                      |
 | 3 | EU Date Of Birth            | Date of birth of the individual                                  |
 | 4 | EU Member State             | Memberstate in EU where the individual has taken the tests |
-| 5 | EU Unique Certificate Identifier | Unique identifier, if any, of the issued certificate             |
+| 5 | EU Unique Certificate Identifier (Duplicate check identifier) | Unique identifier, if any, of the issued certificate             |
 | 6 | EU Disease                  | Disease or agent targeted |
 | 7 | EU Type of Tests            | The type of the test used, based on the material targeted by the test. Example: "tt": "LP6464-4" (Nucleic acid amplification with probe detection), "tt": "LP217198-3" (Rapid immunoassay)  |
 | 8 | EU Test Name           | The name of the nucleic acid amplification test (NAAT) used. The name includes the name of the test manufacturer and the commercial name of the test, separated by a comma. |