ALV Report

Hi,

Can anyone help me out by telling me what this the function of this piece of code:

TYPES: BEGIN OF SLIS_LISTHEADER,

TYP(1) TYPE C, " H = Header, S = Selection, A = Action

KEY(20) TYPE C,

INFO TYPE SLIS_ENTRY,

END OF SLIS_LISTHEADER.

Actually i was going thru a doc. of ALV Report. Just could not find out what the above code means & what it does.

Thanx,

Mohit.