Attachments: Up to 2 attachments (including images) can be used with a maximum of 512.0 KiB each and 1.0 MiB total.
The World-Check Data File is available in XML and CSV formats and includes compressed versions and security checksums. It is also available in the Dynamic Download and Customized Data File formats.
source of information
Error in World check file download
World-Check Premium and Standard file format