Canon EOS R6 Advanced User Guide - Page 705

Auto Reset For restarting file numbering from 0001 after switching cards or creating folders File numbering is reset to 0001 if you replace a card, create a folder, or switch the target card (as in → ). This is useful if you want to organize images by cards or folders. Note that file numbering may continue from any existing images in cards or folders that you switch to. If you want to save images with the file numbering starting from 0001, use a newly formatted card each time. File numbering after replacing cards or switching target cards Card A ( ) Card B ( ) (1) File numbering is reset File numbering after creating a folder Card A 705