Scrolls can be “corrupted” or “misspelled”. This basically acts as a toggle on whether the confused behavior of the scroll activates: reading a corrupted scroll while not confused will produce the confused effect and reading it while confused will produce the regular effect. There is no way to restore a corrupted scroll to normal.

Possibly, an unidentified corrupted scroll will have its label deterministically garbled similar to engravings, e.g. “scroll labeled FO0B|E BLe7Ch”. If identified it would simply show as “corrupted scroll of X”.

Writing a scroll while confused will make the result corrupted. Also, scrolls hit by water damage or produced from polymorphing other scrolls may be corrupted.