gtk-list-store-insert-before (store sibling)

store -- a gtk-list-store object
sibling -- a valid gtk-tree-iter iterator, or nil

A gtk-tree-iter iterator to the new row.

Inserts a new row before sibling. If sibling is nil, then the row will be appended to the end of the list. The returned iterator will point to this new row. The row will be empty after this function is called. To fill in values, you need to call the functions gtk-list-store-set or gtk-list-store-set-value.