.VAULT File Extension
File TypeFontcase Vault File
What is a VAULT file?
Data file created by Fontcase, a font manager for Mac OS X; saves the list of imported user, shared, or system level fonts; also saves the activation or deactivation status of each font as well as other metadata such as ratings.
VAULT files are not opened directly by the user. Instead Fontcase saves them automatically in the [user]/Library/Application Support/Fontcase/ directory.
NOTE: Fontcase was discontinued in 2013.