C-F3F3 Doubly symmetric I-shaped members with compact webs and noncompact or slender flanges bent about their major axis

Section F3 is a supplement to Section F2 for the case where the flange of the section is either noncompact or slender (see Figure C-F1.1 where the linear variation of $M_{n}$ between $\lambda_{p f}$ and $\lambda_{r f}$ addresses noncompact behavior and the curve beyond $\lambda_{r f}$ addresses slender behavior). As pointed out in the User Note of Section F2, very few rolled wide-flange shapes are subject to this criterion. However, any built-up doubly symmetric I-shaped member with a compact web and a noncompact or slender flange would require use of the provisions in this section.