in sense "(Le Système international d'unités; International System of Units) Bureau international des poids et mesures"
x1 is the BIPM (French: Bureau international des poids et mesures; English: International Bureau of Weights and Measures) designation/result/standard/code for topic x2 applied to specific case/individual/group/entity/idea/thing x3 according to rule/BIPM specification x4 published by/according to mandating organization x5 (default: BIPM)
x1 (collection, body, set, mass, tuple, n-some, etc.) is x2 (li; default: 1) indivisible/atomic/elementary/basic discrete entities (or particles) of type x3 in composition/content, by standard x4; the count of instances of x3 in x1 is x2 by standard x4.
x1 is the elementary unit (quantum) of angular momentum/half of Planck's reduced constant [id est: hbar/2 = h/(4 pi)] expressed in units x2 (default: unitless/dimensionless and so that it is equal to 1) in paradigm/system/metaphysics/universe x3 (default: this, our actual, physical universe)