The Protect record specifies the protection state for the sheet or workbook. If this record exists in the Globals Substream, then the protection state specified in this record applies to the workbook. If this record exists in a worksheet substream, chart sheet substream, macro sheet substream, or dialog sheet substream, then the protection state specified in this record applies to only that sheet. This record MUST exist for the workbook. For a sheet, the sheet is protected if and only if this record exists.
fLock (2 bytes): A Boolean (section 2.5.14) that specifies whether the sheet or workbook is protected. For a sheet, fLock MUST be 0x0001, and it means the sheet is protected. For the workbook, it MUST be a value from the following table:
The workbook is not protected.
The workbook is protected.