[cheflo]

The Pocketbook support team just answered my question:

All Pocketbook devices support PDF and offer notes function.
The notes are saved in .html format and can be edited.
If the PDF file is a scanned one, the notes are saved as pictures and can be saved but cannot be edited.

To extract the notes from the device onto the PC, you should connect the device to the PC and find system/config/Active Contents or system/profiles/name_profile/config/Active Contents (if several profiles are activated);