A structure the name of which implies the presence of one or more characteristic groups and which has one or more hydrogen atoms attached to at least one of its skeletal atoms or one of its characteristic groups, or in which at least one of its characteristic groups can form at least one kind of functional modification.
Note:
A @P04405@ bearing a characteristic group denoted by a suffix, for example, cyclohexanol, is not considered to be a functional parent, but may be described as a 'functionalized @P04405@'.
Source:
Blue Book Guide, p. 13 (https://doi.org/10.1351/pac199971071327)