I'm not exactly sure if this is correct, but the military used to use a letter in its specifications corresponding to the component type, e.g., Mil-R-6106 for Relays, Mil-M-38510 for Microcircuits, Mil-P-55110 for Printed Wiring Assemblies. The PRF designation came about as the specs changed to "performance" specifications as opposed to specific device specifications. 

Blair 

>>> [log in to unmask] 07/31/03 01:37PM >>>
Hi Franklin,
For what it's worth-

MIL-P-55110 Rev D, dated 12/31/84 was revised to MIL-PRF-55110 Rev E,
dated12/31/93.  I don't know what the "P" and "PRF" denote.

Regards,
Mark Hargreaves

        -----Original Message-----
        From:   Franklin D Asbell [SMTP:[log in to unmask]] 
        Sent:   Thursday, July 31, 2003 10:23 AM
        To:     [log in to unmask] 
        Subject:        [TN] 55110

        Can anyone tell me the difference between

        MIL-P-55110

        and

        MIL-PRF-55110

        Have a drawing where MIL-P-55110 is noted.

        Thanks

        Franklin


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