ensure the secure storage of passport stamps in locked safes between shifts. Border posts are advised to set out clear responsibilities and instructions for the distribution and use of passport stamps. According to European Commission recommendations and guidelines, stamps should be affixed in travel documents by border officials in the following manner: in chronological order in a horizontal position in a clear and straight manner (i.e. with enough ink and not over the edge of a page) the exit stamp should be affixed in the proximity of the entry stamp no stamp should be affixed over another stamp or over the machine readable zone of a visa if the travel document contains a single-entry Schengen visa, the stamp should be affixed over the edge of the visa, but without affecting the legibility of the conditions and security features of the visa if the travel document contains a multiple-entry Schengen visa, the stamp should be affixed on the page facing the one on which the visa is affixed If a third-country national is refused entry to the Schengen Area, the border official is required to affix an entry stamp in the travel document, cancel the stamp by an indelible cross in blank ink and write the letter corresponding to the reason for the refusal of entry to the right-hand side of the cancelled stamp. By contrast, if a border official has affixed a stamp in a travel document by mistake (as opposed to a refusal of entry), the stamp can be annulled by drawing two parallel lines through the top left-hand corner. In view of the coronavirus pandemic, starting from 16 March 2020 there is a temporary restriction on the entry of third-country nationals (i.e. travellers who are not EU/EEA/Swiss/British citizens and family members with the right of free movement) to the Schengen Area for non-essential travel. However, third-country nationals who are holders of long-term visas or residence permits or are family members of EU/EEA/Swiss/British citizens are exempt from this restriction. Further, third-country nationals 'with an essential function or need' (such as healthcare workers, transport personnel, aid workers, military personnel, seasonal agricultural workers), passengers in transit, those travelling 'for imperative family reasons' and those 'in need of international protection or for other humanitarian reasons' are exempt from this restriction. Citizens of the European micro-states (Andorra, the Holy See, Monaco and San Marino) are also exempt from this restriction. In addition, citizens