Canon EOS REBEL XS Instruction Manual page 41

Formatting the Card
About Low-leveJ Formatting
® Do Iowqevel formatting if the card's recording or reading speed seems
slow.
® Since low-level formatting will erase all recordable sectors in the card, the
formatting will take slightly longer than normal formatting.
® You can stop the low-level formatting by selecting [Cancel]. Even in this
case, normal formatting will have been completed and you can use the
card as usual.
d_
When the car_ is formatted, oniy the file management information is
cnanged. The actual data is not completely erased. Be aware of this when
selling or dLscarding the card, When discarding the card. execute low-level
forma[ung or destroy the card physically to prevent £he data from being
tea<ed.
The care s capacity dlspJaye_ on the format screen may be lower than the
capacity indicated on the card
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