https://learn.microsoft.com/en-us/openspecs/office_file_formats/ms-odcff/09a237b3-a761-4847-a54c-eb665f5b0a6e
[MS-ODCFF]: Office Data Connection File Format | Microsoft Learn
Specifies the Office Data Connection File Format, which is used for specifying data connection information that can be used
data connectionfile formatmsofficemicrosoft