These guidelines are not a comprehensive inventory of all possible categories of skills, knowledge, and attitudes for inclusion in citizen science. Moreover, the absence of certain skills, knowledge, or attitudes identified in these guidelines should not be considered as a reason for exclusion or discouragement of interested stakeholders from participation. We hope this is an informative resource for cities, the citizen science community, and those who are interested in the broader topics of competencies for public participation and stakeholder engagement. These guidelines result from a co-creation process led by Eurocities in close collaboration with the CitiMeasure Digital Inclusion working group members. The co-creation process included a joint effort to identify and share relevant resources and experiences and collaborative analysis, synthesis, and sense-making of the identified resources. 5