A "pseudo" 5x7 dot matrix font (albeit not really), which is designed in a manner to increase readability as in a sans serif font like Arial.
The reason it's called "RNTG" is because it's the work for a fictional communication standard.
Update (12 Nov '17): Support for the Greek alphabet added.
This is a cloneBased on the lettering used for London Underground Jubilee Line 1996 stock PIS (Passsenger Information System) displays.
This is a clone of London Underground 1995 Stock PISBased on the lettering used on the London Underground Northern Line 1995 Stock Passenger Information System.
Based on the London Underground Victoria Line 2009 Stock Passenger Information System.
Based on the lettering used for London Underground S Stock trains (S7/S8 Circle, District, Hammersmith & City and Metropolitan lines).
Lettering based on the Great Western Railway (GWR) 'Thames Turbo' Class 165 and 'Thames Express' Class 166 Passenger Information System.
Based on the lettering used for the original London Underground Jubilee line Extension station Passenger Information System.
Lettering based on the London Underground 1986 Stock Passenger Information System, specifically, the 'red' train.