The first series of handicap plates.
Note the unusual font (unique to the HCP-prefixed and suffixed plates, I think) and the extra-large wheelchair emblem (see also the HAA & HAB plates.) This series may have been provided by a different plate manufacturer from the usual plates, because I haven't seen this font anywhere else.
Note that some of these plates have alphabetic characters as a suffix, not a prefix. Only a few other plate types do this. See the Alaska License Plate Pattern Rules for more information.
Prefixes from DAA-DEZ are reserved for future use as Disabled Vet plates.
According to the Anchorage DMV, some DBx plates (like the ones below) were accidentally manufactured without an emblem in the middle, but were distributed anyway. This could make them more valuable as collectors' items.
I've seen a couple of sources say that you can choose to not have the wheelchair symbol on the Disabled Vet plates, but I haven't seen any with the symbol missing other than these "mistake" DBA plates.
From AS 28.10.181:
(d) Vehicles owned by disabled veterans, including persons disabled in the line of duty while serving in the Alaska Territorial Guard, or other persons with disabilities. Upon the request of a person with a disability that limits or impairs the ability to walk, as defined in 23 C.F.R. 1235.2, the department shall (1) register one passenger vehicle in the name of the person without charge; and (2) issue a specially designed registration plate that displays (A) recognition of the disabled veteran if the applicant's disability originated from the applicant's service with the Alaska Territorial Guard or the armed forces of the United States; and (B) the standard symbol of disability (the wheelchair logo). A disabled veteran who is not otherwise qualified under this subsection, but who presents to the department written proof that the person is at least 70 percent disabled or medically handicapped as a consequence of service in the Alaska Territorial Guard or the armed forces of the United States, may register one passenger vehicle without charge, and the department shall issue a specially designed registration plate that displays recognition of the disabled veteran that does not display the standard handicap symbol and does not carry with it special parking privileges. For purposes of this subsection, proof of disability may be provided by a person licensed as a physician under AS 08.64 or as an advanced nurse practitioner under AS 08.68.
A Disabled Veterans web site.
I don't have a lot of details on these yet, but they've been out for a few years.
Note that, starting around HBF, the plates are fully embossed:
Not yet spotted: [HBH-]
It appears that [HAD], [HAG], and [HAM] were deliberately omitted.