Deliberately un-readable SD Card sectors

[G109B]

What is recorded in an imgc file when an unreadable sector is found ?
I have an imgc file containing many instances of the text "omg!" and "lol!".
I suspect that the original card contained bunches of deliberately un-formatted sectors which HDDRaw has to skip.
How can I list these sector numbers, and more importantly, replicate the situation on restoring to a new card ?

[HaQue]

SD Spec contains some secure features that are not easily reproducible when just imaging through standard user mode apps. Might pay to have a read of the spec.

Commonly used in things like GPS Data add on packs for Sea Vessels, and other software packs for certain devices where you have to pay mucho $$$ and copying them is not a scenario the vendor wants

Also recently there was a discussion about cash register cards from (IIRC) Italy where the data had to be saved to an authorised SD Card for the purpose of taxation.

Is your card in the category of software or special purpose? or just a user card that is suspicious?

[G109B]

Thanks HaQue, I'll have to check.
If the card turns out to be "special purpose" I will tell the owner to forget it.