1 For exceptions to the filing requirement see chapter 2 of Publication 557 and the general instructions for Form 990.  An organization exempt under a subsection of Code sec. 501 other than 501(c)(3) may establish a charitable fund, contributions to which are deductible. Such a fund must itself meet the requirements of section 501(c)(3) and the related notice requirements of section 508(a).
At each APO, FPO, or DPO, there is an equivalent to a-real-honest-to-goodness-Post Office staffed by members of the respective branch of service. While the layout of each APO/FPO/DPO varies by location, suffice it to say they look and operate just like a real Post Office. In fact, they have to, since we are talking about U.S. Mail. Each APO/FPO/DPO address holder has a mail lock box in which their mail is slotted. Since parcels can't fit in these boxes, delivery or notification slips, just like real ones, are put in the boxes whenever a parcel arrives.
PPPoE is a network protocol used for encapsulating data frames over Ethernet networks. That means PPPoE is essentially a Hulked-out version of the old PPP protocol. The main improvement it brought is the fact that PPPoE allows a single server connection to be divided between multiple clients, using Ethernet.