It is usually easiest to order parts and documentation by phone because you
can ask questions, but when you do make sure you have the supplier read back
your order to you to make sure nothing was missed.
This is why it is usually best to fax or email an order. That way you have
written record of what was ordered. This is especially important if wrong
items or quantities are shipped. If you do use fax or email, be sure to
request a confirmation--sometimes fax and email messages are lost enroute
and you have no idea that the order was not received.