The outboard and inboard midplane loci carried a per-dataset height: the height the data's midplane identifier selected, and the magnetic-axis height when none was given. A name whose quantity is taken at a stated height therefore read two heights. Under the lead ruling in concept-and-notation-registry §10 the midplane is now defined once, by the major-radius extremum of the flux surface in question: maximum on the low-field side for the outboard midplane, minimum on the high-field side for the inboard midplane.

Changed paths: imas_standard_names/grammar/vocabularies/conventions/concepts.yml, imas_standard_names/grammar/vocabularies/locus_registry.yml, tests/grammar/test_locus_definitions_physics_only.py. Commit 4c044f1, base 2451ab4.

Definitions changed

Every other locus definition was read. None restates the midplane height. midplane defines the reference plane itself on which the vertical coordinate is zero, not a selected height, and is unchanged. first_wall_midplane names the specified tokamak midplane without a height. dr_dz_zero_point keeps its geometric definition. separatrix keeps its pointer to outboard_midplane_separatrix.

Red controls

Each test fails when the code it guards is removed, shown above; the two new relation tests pass at head (logs/focused-head.log: 6 passed, EXIT=0).

Gate

tests/grammar/ at base 2451ab4: 1282 passed, 32 skipped EXIT=0 (logs/base-tests-grammar.log). At head 4c044f1: 1285 passed, 32 skipped EXIT=0 (logs/head-tests-grammar.log). Zero added failures; the three extra passes are the relation tests this node added.