Differentiate special GL and normal items in FBL1N

Hi,

I've understand that anything that has the Sp. G/L trans.type and Special G/L ind. must be the special GL transaction. But I've found out that some transactions under below criteria is parked under normal items and special GL in FBL1N. Why is that?

Sp. G/L trans.type : A

Special G/L ind. : 7