You are referring to section 5.2.1 if I am not correct, not 3.2.1?
no, section 3.2.1 in current git version of YP development tasks manual. that manual doesn't even have a section 5. we better make sure we're looking at the same manual.
The context is important here. 5.2.1 is discussing using the variable as part of your local.conf. Which is a different animal then adding it to an image recipe. In local.conf you really need _append to for it to even take effect, where its more correct and natural in my opinion to use += in bb since it provides more flexibility to alter the recipe with out using too much magic.
