and protonation at a different position of the anion; and
* acids, involving a series of steps: protonation, formation of a delocalized cation, and deprotonation at a different position adjacent to the cation).

thumbTwo specific further subcategories of tautomerizations:
*Annular tautomerism is a type of prototropic tautomerism wherein a proton can occupy two or more positions of the heterocyclic