These are "in-kind" donations, as you are not receiving cash. Assuming you are receiving a fully or partially paid-up policy, you are receiving an asset that must either be sold for cash or realized upon the donor's death.
IRS Publication 561 is the authoritative source for all property donations - including life insurance. Please see page 7.
When a donor transfers the policy, the insurance company must provide a statement (IRS Form 712) reflecting the "interpolated terminal reserve" value of the property. That value is recorded as a property donation. If the policy is not fully paid and the donor continues to make premium payments, those are cash contributions.
Further substantiating these as property gifts is the donor's requirement to file an 8283 to claim a deduction. As with any other property donation, the donor may also be required to obtain an appraisal for that property.
This link offers a nice summary provided by Crescendo:
I have also attached a pamphlet from planned giving experts, the Sharpe Group, which is useful in your discussions. Pages 11 & 12 discuss the appraisal, 8283, and 8282 requirements.
John