constitutional isomerism

https://doi.org/10.1351/goldbook.C01285
@I03294@ between structures differing in @C01282@ and described by different line formulae e.g. CH3OCH3 and CH3CH2OH.
Source:
PAC, 1996, 68, 2193. (Basic terminology of stereochemistry (IUPAC Recommendations 1996)) on page 2205 [Terms] [Paper]