Transferability assumes invariance of properties, associated conceptually with an atom or a fragment present in a variety of molecules. The property, such as @E01990@, @N04251@, @C01036@, etc. is held as retaining a similar value in all these occurrences.
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1173 [Terms] [Paper]