VBAPD-EPMEH (Do multiple schedule line exist?)

Hi All,

I just wanted know about the standard logic of VBAPD-EPMEH.

I came to know that if line items have more than one schedule lines, this field will be marked as X.

But, in my case, I am having a Sales order with 2 line items and each line item is having only one schedule lines,

and I can see that the field VBAPD-EPMEH and XVBAP-EPMEH is marked as X.

Please help me to understand the standard logic to update this field, if you have any idea about this.

Thank you!