Flap Drawing “B” Question (photo)

[NSLaw]

Hi All -

I might very well be more dense than others but I can’t for the life of me figure out what this B means. See photo. It’s near where a trailing rib will be but not precisely.

any thoughts? Trailing rib?

Thanks!!

[AZBearhawk272]

That is the indication of where a section view was taken and which direction the view was looking.
There should be a corresponding cross section,
Section B-B.
Kevin D
# 272

[NSLaw]

Thank you Kevin.