*  Add a Prepayment type Payment Terms in Sales => Payment Terms page
* Create a Deferred Income Account in the Chart Master under Current Liabilities if one does not exist, say in the Standard CoA's as 2105
* Choose this Deferred Income Account in the Banking and GL Setup page under the same head.

Now we can make a Sales Order with the Payment Terms as Prepayment, accept payments for it and then invoice the Prepaid Order.

Deferred Income Account

As on date, none of the official Charts of Accounts including the Standard ones have a Prepaid Type Payment Term and Deferred Income Account by default.

Deferred revenue is not yet revenue. It is an amount that was received by a company in advance of earning it. The amount unearned (and therefore deferred) as of the date of the financial statements should be reported as a liability. The title of the liability account might be Unearned Revenues or Deferred Revenues.

The Wiki has been updated.
My FA24Mods repo stands committed.

@joe: Please add in the Prepaid Type in the list of available Payment Terms along with a Current Liability type Account 2105 - Deferred Income Account - in all the charts (Standard and official packages).