Files with fno extension are associated with an old program Infobase.
There is one other file type using
the FNO file extension!
.fno - Atlast File Notes Organizer CSV data file
FNO file extension - Folio Infobase file
What is fno file? How to open fno files?
File type specification:
The fno file extension was used by older program known as Infobase, an application and data format that appears to be very popular among various governmental agencies. It is apparently also used to produce many CD/DVD titles.