Besides Isotactism, there are other two types of stereoregularity frequently found in the scientific literature:
Syndiotactism- The monomers have alternating orientations within the polymer chain: AB-BA-AB-BA-AB-BA-etc
and Atactism- The monomers have random orientations within the chain:
e.g. AB-AB-BA-AB-BA-BA-BA-AB-etc