When a user touched the link that (s)he received, a response record is added to the response table.
I am not absolutely sure if the response record persists when that user decides to stop and delete all responses. In my experience it rarely happens that users do this, that when you have surveys with specific characters, this may happen more often.
Tammo
Tammo ter Hark at Respondage
For Limesurvey reporting, education and customized themes
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