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Projects that are on a Pro software plan or higher can use the Data Cleaning: Clean Form Submission feature. This allows project staff to make updates or corrections to forms that were previously submitted.
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An app can contain "edit" forms that load in the previous values of case properties, and allow users to update them. This then updates the value of the case property, so that the case details/export contain the most recent values. Details on the workflow can be found at How can your user edit data and a tutorial on how to create the Edit From Form can be found at Edit Form Tutorial.
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