Some of the occupational series covered by this standard include both one- and two-grade interval work. The qualification requirements described in this standard apply only to those positions that typically follow a one-grade interval pattern. While the levels of experience shown for most positions covered by this standard follow the grade level progression pattern outlined in the table, users of the standard should refer to E.3.(o) in the "Policies and Instructions" section for guidance on crediting experience for positions with different lines of progression.