token
The API token specific to your REDCap project and username (each token is unique to each user for each project). See the section on the left-hand menu for obtaining a token for a given project.

content
record

action
delete

records
an array of record names specifying specific records you wish to delete

arm
the arm number of the arm in which the record(s) should be deleted. (This can only be used if the project is longitudinal with more than one arm.) NOTE: If the arm parameter is not provided, the specified records will be deleted from all arms in which they exist. Whereas, if arm is provided, they will only be deleted from the specified arm.

instrument
the unique instrument name (column B in the Data Dictionary) of an instrument (as a string) if you wish to delete the data for all fields on the specified instrument for the records specified.

event
the unique event name - only for longitudinal projects. NOTE: If instrument is provided for a longitudinal project, the event parameter is mandatory.

repeat_instance
the repeating instance number for a repeating instrument or repeating event. NOTE: If project has repeating instruments/events, it will remove only the data for that repeating instance.

delete_logging
provide a value of '0' ("keep logging") or '1' ("delete logging"). This option can only be utilized for projects with the "Delete a record's logging activity when deleting the record?" setting enabled by an administrator on the Edit Project Settings page. If that setting is enabled in the project, then the default value will be '1', and if the project-level setting is not enabled, the default value will be '0'. If the project-level setting has been enabled, this option must be provided with a value of '0' in order to prevent the record's logging activity from being deleted when the record is deleted.