Callback is one word when used as a noun or adjective.
Example: I need to call back two of the top candidates for the
Example: After the audition, Chaital hoped for a callback.
Callout is one word when used as a noun or adjective.
Example: You should call out the processes in the diagram.
Example: The illustration had a callout created as a text box.
|■.||Callouts should have the first letter capitalized.|
|■.||Do not capitalize callouts that start with an ellipsis (…).|
|■.||If the callout is a complete sentence, end it with a period.|