Also contains definition of: nitrogen mustards
Compounds having two β-haloalkyl groups bound to a sulfur atom, as in (XCH2CH2)2S, and their analogues, the nitrogen (and phosphorus) mustards, (XCH2CH2)2NR. Compounds having one β-haloalkyl group and one β-hydroxyalkyl group on S are termed hemi- or semi-mustards by some chemists.
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1350 (