Nikon D610 Reference Manual - Page 657

d7: File Number Sequence G button U A Custom Settings menu Choose a file numbering option. Option [On] [Off] [Reset] Description When a new folder is created or a new memory card is inserted in the camera, file numbering will continue from the last number used. This simplifies file management by minimizing the occurrence of duplicate file names when multiple cards are used. When a new folder is created or a new memory card is inserted, file numbering restarts from 0001. If the current folder already contains images, file numbering will instead continue from the highest file number in the current folder. If you select [Off] after selecting [On], the camera will store the current file number. File numbering will resume from the previously-stored value the next time [On] is selected. Reset the file numbering for [On]. If the current folder is empty, file numbering will restart from 0001 with the next picture taken. If the current folder contains images, the next picture taken will be assigned a file number by adding one to the highest file number in the current folder. Menu Guide > A Custom Settings 611