A file with .nsf (Notes Storage Facility) extension is a database file format used by the IBM Notes software, which was previously known as Lotus Notes. It defines the schema to store different kind of objects such like emails, appointments, documents, forms and views. All this information is contained in a single NSF file for business collaboration similar to a PST/OST file. Some of the applications that can open NSF files include IBM Lotus Notes and IBM Domino.
NSF File Format Specifications
NSF files are binary in nature and their specifications are available by Joachim Metz on Github. As per these details, an NSF file comprises of:
In addition, it consists of:
Bucket descriptor block
Record Relocation Vector bucket
NSF File Header
The NSF file header is a 6 bytes in size. It consists of:
The database header size
The NSD Database header contains the following confirmed values.