What does SH mean on an exam script?

Hi,
I've just gotten my exam script back for AQA English Lit B as I sent it in for a re-mark. There are loads of SH symbols on my paper but neither me or my teacher know what that means. Anyone know??????
Obviously there are other symbols where I know what these mean such as the tick, the cross, the question mark etc, but we have NO IDEA what SH means