What's involved here is a donation of $X in stock that will pay income to the donor for life (or a period of years) with the remainder to a charity, so the value of the donation is Y% of $X.  For example, $10K in stock might result in a $2K deduction.  It's more or less like a charitable remainder trust.  I'm not sure of how that gets shown on a Form 8283, but I doubt that any attachment will be reviewed before IRS decides to examine the return.  (Not that they're doing many audits right now, or for the next couple years.)  In fact, they would probably ask you to provide a copy of the 8283 itself.