This is a tab on the Contact Person page.
To add a phone number, click +. To delete a phone number, click X and confirm.
You have to indicate whether or not a phone number is a mobile phone, because Harvest could send text messages to groups of people to inform them.
If a person does not want to receive text messages, the box Permission To Send Text Messages should be unchecked.
Please note that the current version of Harvest does not support sending group text messages yet. This feature will be implemented in the course of 2014.