Access sequence

Hi!

I have some problem with the following customizing settings.

SPRO - Sales and distribution - Basic functions - Pricing - Pricing control - Define access sequences - Maintain access sequences.

Select first access sequence A001 - choose Accesses from the left side. In this table, which appears, there are 5 columns: AcNo, Tab, Description, Requirement, Exclusive.

What is AcNo and where does it come from??