We have the following informal guidelines for train names:
.
1. When the train connects 2 Regional (non-Hindi speaking) states, then we have English, Hindi & the language of the Departure State.
So,
a. 12134...
more... - Mangalore Mumbai SF should have English, Hindi & Kannada
b. 12133 - Mumbai Mangalore SF (the return journey) should have English, Hindi & Marathi.
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2. When the train train connects a Hindi speaking state and a non-Hindi state, then we have English, Hindi & the language of the non-Hindi state in both directions.
So,
Karnataka Express should have English, Hindi & Kannada in both directions. (since Delhi is considered a Hindi-speaking state).
.
Admittedly, this is not a perfect solution, and there will be differences of opinion. This is JUST an informal guideline that we are following.
Thanks.