According to Note 3 of Table 5.5.2.4-1 in SOL003 v4.4.1 specification, "The target size for VNF instantiation may be specified in either instantiationLevelId or targetScaleLevelInfo, but not both. If none of the two attributes (instantiationLevelId or targetScaleLevelInfo) are present, the default instantiation level as declared in the VNFD shall be used". In the OAS and in particular within the InstantiateVnfRequest component, any of the instantiationLevelId or targetScaleLevelInfo attributes are set as required. In this way, the flavourId and any of the instantiationLevelId or targetScaleLevelInfo are required. This leads to not allowing the flavourId only in the InstantiateVnfRequest request, and then not complying with what is written in Note 3.