Canon EOS-1D X Manual (en)

Image Frame Information in the Main Window and Edit Image Window
Trimming (cropping) range
Check mark
Pinned image setting mark
Multiple image display mark 
Image type
File name
Rating mark
GPS mark
Lens aberration correction mark
Digital Lens Optimizer mark
Unsaved editing content mark
Displayed on RAW+JPEG images displayed as a 
single image 
] is displayed in RAW images.
] is displayed in Dual Pixel RAW images.
When aspect ratio information is attached to an image 
shot with any supported camera other than the EOS 5D 
Mark II, the image is displayed as a cropped image.
Displayed on images shot on a GPS function-
compatible Canon camera.
] is displayed in an image frame when editing is not possible.