ribbon delocalisation

Electron delocalization realized in both acyclic and cyclic π-conjugated, 1, and σ-bonded, 2, ribbon-like systems.
For cyclic systems, a variety of linkage fashions between several ribbons (pericyclic, spirocyclic, longicyclic and laticyclic) is possible.
PAC, 1999, 71, 1919 (Glossary of terms used in theoretical organic chemistry) on page 1961