Description says "Use this attribute only if the country in the 'nation' element has an ISO 3166-1 2-letter code."
/codeBook/stdyDscr/stdyInfo/sumDscr/nation/@abbr is specified as recommended and it causes troubles with the historical data when using standard validation - even if the historical country do not have @abbr it is not valid
Description says "Use this attribute only if the country in the 'nation' element has an ISO 3166-1 2-letter code." /codeBook/stdyDscr/stdyInfo/sumDscr/nation/@abbr is specified as recommended and it causes troubles with the historical data when using standard validation - even if the historical country do not have @abbr it is not valid