SMF to WPForo attachment converter - Documentation about the Database and storage location ?

Hi,

my programmer wants to build a SMF to WPForo attachments converter,

so we need documention, how the attachments are linked into the WP Forum Database...
Is there anywhere this documentation available, if one posts a picture attachment to a WPForo thread, where it is stored in the database and where the attachment file is then really located.. ?
Many thanks in advance,

Regards, STefan.