Materials marked for deletion

Hai,

In MI31 T.Code, we will find one check box as "Materials Marked for Deletion" I can understand that if we select this check box ,materials with delete flags are also take into account for physical inventory process.

But I didnt understand what is the exact meaning of term materials with delete flags, and where we have the option of make delete flag for a material.

Can any body help me.

Thanx & Reagards

T.Krishna Mohan