The IRS published 45 FAQs related to virtual currency (Bitcoin and other cryptocurrency), and foundations should note two of these questions address charitable acknowledgment of such gifts as well as IRS reporting requirements.
Briefly, a contemporaneous written acknowledgment is required for gifts of crypto-currency similar to other gifts, but cryptocurrency is treated as a property gift (other than cash) and may also require completion of IRS form 8283 by the donor depending on the value of the gift.
With respect to IRS reporting, cryptocurrency is reported on the 990 as a non-cash gift, and on Form 990, Schedule M if applicable. Donee organizations must also file IRS form 8282 if all or a portion of the cryptocurrency is sold, exchanged or otherwise disposed of within 3 years. This includes converting the cryptocurrency into cash.
More details including all the other FAQs can be found on the IRS website.