Foursquare was built from the ground up by the entire community! In that spirit, anybody can suggest edits, whether or not they're a superuser. But, for the special few who are superusers, suggested edits carry more weight and are more likely to go through (that means name/address/contact info, merging duplicates, removing places and tips, etc.).
Whereas suggestions from Level 1 superusers are more likely to go through than suggestions from non-superusers, suggestions from Level 2 superusers carry more weight than Level 1, and so forth. All superusers can review suggested edits from other superusers, and popular places require more reviewers. Level 3 upgrades are reserved for superusers who have consistently made valuable edits over time and have proven themselves to be positive leaders in the SU community.
Make sure to check out our superuser resources below: