File extensions that begin with P.

 Ext.  Type of file
 P7S   PKCS #7 signature
 P10   Tektronix Plot10 plotter

 PAK   DOS PAK archive
 PAL   Windows palette
 PAR   Parity
 PAR2  Parity
 PAS   Pascal source code
 PAT   CorelDRAW pattern

 PBD   PowerBuilder dynamic library
 PBK   Microsoft Phonebook
 PBK   Public encryption key
 PBM   Portable Bitmap

 PCH   Precompiled header
 PCL   HP LaserJet series
 PCD   Photo CD bitmap
 PCM   LaserJet cartridge info.
 PCS   PICS animation
 PCT   PC Paint bitmap
 PCT   Macintosh PICT bitmap & vector graphics
 PCW   PC Write document
 PCX   PC Paintbrush bitmap

 PDB   eReader e-book
 PDF   Portable Document Format (Acrobat)
 PDF   Printer driver
 PDF   Printer description (QuarkXpress)
 PDV   PC Paintbrush printer driver
 PDW   HiJaak vector graphics

 PFA   Type 1 font (ASCII)
 PFB   Type 1 font (encrypted)
 PFM   Windows Type 1 font metrics

 PGL   HPGL 7475A plotter (vector graphics)

 PIC   Various vector formats:
 PIC   Lotus 1-2-3
 PIC   Micrografx Draw
 PIC   Mac PICT format
 PIC   IBM Storyboard bitmap
 PIF   Windows info. for DOS programs
 PIF   IBM Picture Interchange
 PIN   Epic Pinball data
 PIT   Macintosh Packit archive
 PIX   Inset Systems raster & vector graphics

 PKG   NextStep installer package
 PKG   Sybase package of installation files
 PKR   PGP public key (public keyring)

 PL    Perl script
 PLS   Playlist
 PLT   AutoCAD plotter file
 PLT   HPGL plotter file

 PM    PageMaker graphics/text
 PMx   PageMaker document (x=ver.)
 PML   PageMaker library

 PNG   PNG bitmap

 POTX  PowerPoint template (Open XML)
 POTM  PowerPoint template and macro (Open XML)
 POV   POV-Ray ray tracing

 PP4   Picture Publisher 4
 PPAM  PowerPoint add-in (Open XML)
 PPD   PostScript printer description
 PPM   Portable Pixelmap
 PPS   PowerPoint slide show
 PPSM  PowerPoint slide show and macro (Open XML)
 PPSX  PowerPoint slide show (Open XML)
 PPT   PowerPoint
 PPTM  PowerPoint macro
 PPTX  PowerPoint (Open XML)

 PRD   Microsoft Word printer driver
 PRE   Lotus Freelance
 PRF   Outlook profile settings
 PRG   dBASE source code
 PRN   XyWrite printer driver
 PRN   Temporary print file
 PRS   WordPerfect printer driver
 PRS   Harvard Graphics
 PRT   Formatted text

 PS    PostScript page description
 PS1   PowerShell script version 1
 PS2   PowerShell script version 2
 PSD   Photoshop native format
 PSR   Powersoft report
 PST   Outlook backup (Personal Folder)

 PTx   PageMaker template (x=ver.)

 PUB   Microsoft Publisher publication
 PUB   Ventura Publisher publication
 PUZ   Across puzzle

 PVK   Private encryption key

 PWL   Windows password list