lsb-fhs tests the Filesystem Hierarchy aspects of the Linux Standard Base. The V1.0 and V2.1-X tests correspond to FHS2.0 and FHS2.1, respectively, and are now obsolete. The V2.2-X tests correspond to the FHS2.2 specification. The 2.2 tests are the current tests used for LSB 1.3 certification. The V2.3-X tests correspond to the FHS 2.3 specification and will replace the V2.2 tests for LSB 2.x certification. The V2.3 tests have yet to be formally approved by the LSB test team.