Train 18 - तेरी प्यारी प्यारी Livery को किसी की नज़र न लगे

I am planning to book ticket in 1AC (Coupe for couples), I got information that seats in Coupe / Cabins in 1AC are not allotted at the time of booking (though well in advance 120 days) and the same are allotted at the time of preparation of chart on actual date of journey. Even if, I exercise my option (preference of Coupe) while booking, I may or may not get Coupe (not confirmed).
Is it really practice or I just got misleading information..!!

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