PTA Subway, Uptown bound R68 NIS D train arriving at Fairview Ave

Taken 2/26/24
As you can see, here we see an Waterside yard bound R68 NIS signed as D train deadheading to yard bound after completed the D train route for the day and it's making way back to the Waterside yard bound.

[@Trainfan_YT]

How does it have NIS sign on the front and D sign at the back

[@r179ztrainproductionsgamin6]

Nex's activities.