++++ 1. Social security for migrant workers ° Sickness insurance ° Worker going to another Member State ° Retention of entitlement to benefits ° Limited to a three-month period ° Extension not requested but application for benefits lodged shortly before the expiry of the period with the institute of the place of stay ° Obligation of the competent institution to examine the possibility of an extension (Council Regulations Nos 1408/71, Art. 25(1) and (4), and 574/72, Art. 26(6)) 2. Social security for migrant workers ° Sickness insurance ° Worker going to another Member State ° Retention of entitlement to benefits ° Limited to a three-month period ° Extension ° Force majeure ° Concept ° Appraisal by the competent institution of the circumstances of the case (Council Regulation No 1408/71, Art. 25(4))