This action assigns map numbers to atoms of a molecule or a reaction. Map numbers are assigned in a given order to each atom of the input structure.
Options in case of reaction file input:

• Select the mapping style as Complete, Matching, or Changing.

• Map action can also Mark bonds that have changed in the reaction.

• Keep existing mapping (on by default)

Note : Reactions are mapped by the AutoMapper User's Guide tool.

Example :