FOAM 0.10 has alpha-quality (not feature complete) functionality in the Sliver Analysis Engine to check VLAN overlap. This feature is missing a lot of checks to handle hybrid switch interactions with non-hybrid switches, issues with vlans in hybrid flowspaces, higher-layer protocol segmentation by vlan, etc. This feature is disabled by default and it is not recommended to enable it without discussion with either Nick Bastin or Josh Smift such that you understand exactly how it works.
The rest of this document entails what VLAN analysis engine support will be, not what it currently is.
VLAN Approval Flow