Canon EOS-1D X Instruction Manual page 263

Using the <J> Button
Under [85:J/Kbutton function], if you set [Rating (J and K
disabled)] (p.338), you can press the <J> button to rate images/
movies during playback.
The total number of images with a given rating can be displayed up to 999. If
there are more than 999 images with a given rating, [###] will be displayed
for that rating.
Taking advantage of ratings
With [32: Image jump w/6], you can display only images and
movies with a specific rating.
With [32: Slide show], you can play back only images and movies with
a specific rating.
With Digital Photo Professional (provided software, p.418), you can
select only images and movies with a specific rating.
With Windows 8, Windows 7, and Windows Vista, you can see each file's
rating as part of the file information display or in the provided image
viewer.
Set the <
1
J
Set [85:J/Kbutton function] to
[Rating (J and Kdisabled)].
Playback the image.
2
Turn the <5> dial to select the
image or movie to be rated.
Rate the image or movie.
3
Each time you press the <J> button,
the rating mark will change: l/m/
n/o/p/None.
To rate another image or movie,
repeat steps 2 and 3.
Setting Ratings
> button's function.
263