API 650 Figure F-2 confusion

[APITankman]

API 650 figure F-2 has seen some changes (looking at the most recent version: 12th, March 2013)

I'm confused.

In order to calculate the participating area of the Shell/Roof/Angle there are formulae for Wc, Wh, R2 which are all fine for me, however, in most of the details now there appears to be a dimension Le?. There is no mention of this dimension in the legend below the figures or a formula to calculate its length or is this simply the leg length of the angle as specified in the data sheet?

Also, In the legend it states that "tf = ta plus tc (see note 4)". I might need glasses but where are all the notes?. I've read through App.F several times just in case I've missed them but to no avail.

Can anyone shed any light?.

Cheers,

 

[IFRs]

the notes did not make if from the previous edition.
unfortunately, this is not unique to this figure.
the previous notes included a definition of Le and were:

Notes:
1. All dimensions and thicknesses are in mm (in.).
2. Dimension B in details b, c, d, and e is: 0 ≤ B ≤ C. C is the dimension to the neutral axis of the angle.
3. The unstiffened length of the angle or bar, Le, shall be limited to 250t/(Fy)1/2 mm [3000t/(Fy)1/2 in.] where Fy is the minimum specified
yield strength, MPa (lbf/in.2) and t = ta or tb, as applicable.
4. Where members are lap welded onto the shell (refer to details a, b, c, and g), tf may be used in wc formula only for the extent of the
overlap.