This term has improperly been used for alkylideneaminoxyl radicals, also called iminoxyl radicals
R2C=N–O·. Its use is strongly discouraged.
See: aminoxyl radicals, iminyl radicals
Source:
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1343 (https://doi.org/10.1351/pac199567081307)