Groups formed by removing one or more hydroxy groups from oxoacids that have the general structure RkE(=O)l(OH)m
(l ≠ 0), and replacement analogues of such acyl groups. In organic chemistry an unspecified acyl group is commonly a carboxylic acyl group. E.g.
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1311 (https://doi.org/10.1351/pac199567081307)