Canon WFT-R10A Wireless File Transmitter for EOS R5 C & R5 Mirrorless Camera - Manual (Page 121)

4.
Select [OK].
The camera will automatically configure the file name starting from
WFTNPF01 and up to 10.NIF. By pressing the
〈 〉 button, you
can specify a file name. (The length is fixed to eight characters.)
The settings are saved on the card.
The settings information file is saved in the location where the card is
opened (on the root directory).
Caution
Up to 40 settings information files can be saved on a card for the camera. To save
41 or more files, use another card.
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