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If duplicate filenames are allowed, a user can upload a file with the same name as a file that already exists.
If duplicate filenames are not allowed, the user will get one of two messages depending on their access to the file with the same name.
If they have delete access to the existing file of the same name, they will be given the choice to either option overwrite the file. If they choose not to, the upload will be canceled.
If they do not have delete access to the existing file, they will be told they cannot upload a file of the same name, and be asked to rename their file and try again.
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