What does RI stand for?
RI stands for "Relay Interlocking"
How to abbreviate "Relay Interlocking"?
"Relay Interlocking" can be abbreviated as RI
What is the meaning of RI abbreviation?
The meaning of RI abbreviation is "Relay Interlocking"
What does RI mean?
RI as abbreviation means "Relay Interlocking"