TED reference MUST match '[][][][]/S [][][]-[][][][][][]' (e.g. 2015/S 252-461137).
cac:AdditionalDocumentReference[normalize-space(cbc:DocumentTypeCode) = 'TED_CN']
matches(normalize-space(cbc:ID/text()), '^[0-9]{4}/S [0-9]{3}\-[0-9]{6}$')