[1] Parent structures underpin systematic nomenclature and facilitate classification.
Fundamental parent structures have one or no functional groups and often have various types of symmetry.
Some parents are rare or nonexistent themselves, as in the case of porphine, though many simple and complex derivatives are known.
Parent hydrides have a defined standard population of hydrogen atoms attached to a skeletal structure.
Parent hydrides are used extensively in organic nomenclature, but are also used in inorganic chemistry.