patri ke is taraf ya us taraf, zindagi mein hum sab RailFan ek taraf - Ananya D'Souza

Agreed.
while adding Train from this Option. the Loco no. is getting reflected in Train Forum.
but sir ,while adding Loco from train forum. even if u dont add loco no. its getting reflected .
/loco/1218
here...
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check i have added loco for KOAA NJP Spcl (testing ony).
/timeline/entry/802079.
i havent added the loco no.

Yup I know that feature very well and I was the one of the very first admns who used the feature to update when that was introduced.
But please understand that both features are not same. They are introduced for a different purpose.
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People are getting so confused with these two features which are different but making an unwanted impact...
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on the Loco section of a train.
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You are thinking about the locos that haul a train.
I am thinking about trains that are hauled by a Unique loco, which is differentiated by Road Number (Ex: UBL WDP4B #40008). Not a range of same of model of locos from a shed (Ex: all UBL WDP4Bs)
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For example, The Hubli WDP4B #40008 has hauled various trains like 17307 Basava Express., 16534 SBC-JU Express. So to which trains this loco has hauled, you would visit Loco timeline of UBL/WDP4B/40008 not any Train timeline.
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So this feature is correct. But this feature is indirectly updating train's loco section as well with Road number of locos. Which is creating the confusion. Its just that the updation is correct but displaying on the train's time table under "regular locos hauling the train" section is unwanted.
Its a Site-Related issue and Hence the issue has been escalated to #moderator and response awaited.