1. Before entering an alert, the Member State shall check whether the person concerned is already the subject of an alert in SIS. For that purpose, a check with dactyloscopic data shall also be carried out if such data are available.
2. Only one alert per person per Member State shall be entered into SIS. Where necessary, new alerts may be entered on the same person by other Member States, in accordance with paragraph 3.
3. Where a person is already the subject of an alert in SIS, a Member State wishing to enter a new alert shall check that there is no incompatibility between the alerts. If there is no incompatibility, the Member State may enter the new alert. If the alerts are incompatible, the SIRENE Bureaux of the Member States concerned shall consult each other by exchanging supplementary information in order to reach an agreement. Rules on the compatibility of alerts shall be laid down in the SIRENE Manual. Departures from the compatibility rules may be made after consultation between the Member States if essential national interests are at stake.
4. In the case of hits on multiple alerts on the same person, the executing Member State shall observe the priority rules for alerts laid down in the SIRENE Manual.
If a person is subject to multiple alerts entered by different Member States, alerts for arrest entered in accordance with Article 26 of Regulation (EU) 2018/1862 shall be executed as a priority, subject to Article 25 of that Regulation.