databases will remove fontd System or User databases along with any cache files. Removing databases may cause the loss of font registration state: fonts activated outside the standard font directories, font faces disabled, and font libraries. New databases will be regenerated from fonts installed the standard font directories after the user logs out, restarts, or the fontd server is restarted.
-remove remove fontd databases for active user and system (used when no one is logged in and some background processes).