What is a BDO file? A BDO file is a Binding Data Object, saved in a format defined by the NATO Standardization Office's (NSO) Allied Data Publication 4778. BDO files are .XML files, which are used to associate metadata with a data object. BDO files may be digitally signed, to verify their authenticity.

More Information In 2020, the NSO defined standards that NATO members could use to apply metadata to data objects, in hopes that doing so would allow for more efficient information management. The document that defined these standards was Allied Data Publication (ADatP) 4778. As part of defining these standards, the NSO created the BDO file format. BDO files contain XML-formatted information used to bind (associate) a data object with a metadata label. This binding may be either a detached or encapsulating binding.