Options when creating custom field
If you are not sure which option should be selected, we suggest you to select all of them.
Visible and Editable in Contact Manager is important so that you can select fields in contact manager and edit them.
Available when creating forms is used in fields list custom fields. This options provides you access to custom fields inside your forms.
Email merge variable is used in your email templates to make them more personalized. Example: If you wanna use First Name inside your email to say Hello {First Name}, Email merge variable is required in that case. This option is also required if you would like to use the field for Dynamic Email Content.