| 8 | === General properties of the CMD profile schema definition === |
| 9 | |
| 10 | A CMD profile schema `MUST` be a single document {or set of linked documents with a single entry point}(?) that allows for the evaluation of a CMD instance on all levels of description defined in one specific CMD profile. |
| 11 | The schema `MUST` require the presence of a CMD instance envelope as described in section "Structure of CMDI-files". The value of the `MdProfile` header item `MUST` only be valid if it is equal to the profile id as specified in the associated CMD profile. |
| 12 | |
| 13 | The CMD profile schema `MAY` include, as a matter of annotation, a copy of (a subset of) the information contained in the `Header` section of the CMD profile from which it is derived. |
| 14 | |
| 15 | The transformation `MAY` make use of embedded component identifiers to derive (complex) types that can be reused throughout the schema definition. |