Two projects are given. They use different YP release each.
Projects use also different target platform each.

I wonder if differences in structuring metadata- and recipes- directory tree between
these two projects result solely from different YP releases in use.
Or if these can be a result also of modifications conducted by platform vendors.

Any hints in what extend these result from different YP release numbers in use?

project A (YP release 2.6)
xxxx /yocto/
xxxx/yocto/downloads
xxxx/yocto/meta
xxxx/yocto/sstate-cache
xxxx/yocto/build
xxxx/yocto/.repo
xxxx/yocto/src
xxxx/yocto/prebuilt
xxxx/yocto/meta/
xxxx/yocto/meta/poky
xxxx/yocto/meta/meta-security
xxxx/yocto/meta/meta-clang
xxxx/yocto/meta/meta-openembedded
xxxx/yocto/meta/poky/
xxxx/yocto/meta/poky/meta
xxxx/yocto/meta/poky/documentation
xxxx/yocto/meta/poky/meta-poky
xxxx/yocto/meta/poky/meta-selftest
xxxx/yocto/meta/poky/bitbake
xxxx/yocto/meta/poky/.git
xxxx/yocto/meta/poky/meta-yocto-bsp
xxxx/yocto/meta/poky/meta-skeleton
xxxx/yocto/meta/poky/scripts
+ a set of layers value chain specific, meta-... subdirectories with meta/ as root-point.

project B (YP release 2.0, actually backport of some later release
which unfortunately is not reflected in poky.conf)
yyyy/poky/
yyyy/poky/meta-yocto
yyyy/poky/meta
yyyy/poky/documentation
yyyy/poky/meta-selftest
yyyy/poky/meta-selinux
yyyy/poky/build
yyyy/poky/meta-cust-installer
yyyy/poky/bitbake
yyyy/poky/meta-yocto-bsp
yyyy/poky/meta-skeleton
yyyy/poky/scripts
+ a set of layers value chain specific, meta-... subdirectories with poky/ as root-point.

I mean mainly following differences:
* Project A places a set of value-chain specific layers/meta-... directories at same
directory level as poky.
* meta-yocto apparently not present in project A tree
* meta-poky apparently not present in project B tree