Filter Hook: This filter allows overriding `$main_tags`. Which is used in main email template.

Filter Hook: Allows filtering email template after its prepared, passed be reference.

Filter Hook: Used for registering a default email template for an event.

Action Hook: Hook triggered before an email added to current sending list.

Filter Hook: Can be used to modify `$args` before updating question

Filter Hook: Can be used to modify args before inserting question

Filter Hook: Can be used to modify `$args` before updating answer

Filter Hook: Can be used to modify args before inserting answer

Filter Hook: Filter for modifying answer form `$args`.

Action Hook: Action triggered after rendering field markup.