The calculator in question is the World Health Organization (WHO) Criteria for Polycythemia Vera in Women. This diagnostic criteria is specifically used for women suspected of having polycythemia vera, a rare blood disorder characterized by an increased number of red blood cells. 

The clinical utility of this calculator is to aid in the diagnosis of polycythemia vera. It takes into account various factors such as hemoglobin level, bone marrow biopsy results, presence of JAK2 mutation, and serum erythropoietin level. 

The WHO criteria for polycythemia vera in women is not applicable to patients who do not meet the specific hemoglobin level or those who have secondary causes of erythrocytosis such as chronic lung disease, renal disease, or certain tumors. It is also not applicable to patients with other myeloproliferative disorders.

WHO criteria for polycythemia vera in women

# Criteria
 # Major criteria
A. Hemoglobin > 16 g/dL or hematocrit > 48% or increased red blood cell mass
B. Bone marrow biopsy showing hypercellularity for age with trilineage growth, including prominent erythroid, granulocytic, and megakaryocytic proliferation with pleomorphic, mature megakaryocytes
C. Presence of JAK2 V617F or JAK2 exon 12 mutation
# Minor criterion
D. Subnormal serum erythropoietin level

# Conditions
- (A and B and C) or (A and B and D)
- true