V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

PHB
       PCI Host Bridge (Power4, IBM)


The Jargon File (version 4.4.7, 29 Dec 2003):

PHB
 /P?H?B/

    [Usenet; common; rarely spoken] Abbreviation, ?Pointy-Haired Boss?. From
    the Dilbert character, the archetypal halfwitted middle-management
    type. See also pointy-haired.