Canon 10D User Guide (en)

Sorting Images in the Main Window
You can sort images by attaching three types of check marks in the main 
In the main window, select the images you want to 
sort and attach a check mark for sorting.
The selected check mark appears in the upper left of the image 
Click the [Clear check] button to remove the check marks.
Check mark
Click on desired images while holding down the <Ctrl> key. To select 
multiple consecutive images, click on the first image, and then click on 
the last image while holding down the <Shift> key.
To select multiple images in the main window
You can arrange images in the order of the types of check marks you 
have attached to images, or in the order of date and time at which the 
images were shot. You can also freely arrange images by moving them 
Arranging by Type 
Select the [View] menu   [Sort]   desired item.
The images are arranged in the order according to the selected 
Arranging Images in the Main Window