Canon PowerShot A510 User Manual page 118

Various Functions
Setting the File Number Reset to [Off] is
useful for avoiding file number duplication
when images are downloaded to a computer.
About File and Folder Numbers
Images are assigned file number from 0001 to
9900, and folders are assigned folder
numbers from 100 to 998 (Folder numbers
cannot contain 99 in the last two digits).
Folder numbers cannot contain
99 in the last two digits.
116
Folder File Capacity
Each folder usually contains up to 100
images. However, since images shot in
continuous shooting and Stitch Assist mode
are always saved into the same folder, a
folder may contain more than 100 images.
The number of images may also exceed 100 if
a folder contains images copied from a
computer or images shot with other cameras.
Please note, however, that the images in
folders containing 2001 or more images
cannot be played back in this camera.