The POT file (.pot)

A POT file is a PowerPoint template from the PowerPoint 97 to 2003 era: slide masters, a colour scheme, fonts and often example slides, used as the starting point for new presentations. Using one gives you a new, untitled presentation with a copy of its design and content, and leaves the template unchanged. PowerPoint 2007 replaced it with POTX and POTM, but current PowerPoint and LibreOffice still open POT templates.

Inside, a POT is a PPT presentation, stored in exactly the same binary format, just as a PPS show is.

• It's binary. Masters, slides and text are records inside an OLE2 compound file, not readable XML.
• It can contain macros under the same extension, unlike a POTX.
• Not every .pot file is a PowerPoint template. GNU gettext uses .pot for translation templates; see below.

As far as we could find, nothing inside the file. Word's binary templates have a template bit in their header (see DOT), but in our PowerPoint files there is no equivalent:

• Our samples are identical. LibreOffice 24.2 saved the same template with its "MS PowerPoint 97 Vorlage" filter (.pot; *Vorlage* is German for template) and its "MS PowerPoint 97" filter (.ppt). The two files match byte for byte, all 97,280 of them. The same is true of its PowerPoint 97–2003 AutoPlay output (PPS).
• The class ID, the CompObj stream and the MIME type are the same as in a PPT.
• The file command reports both as "Composite Document File V2 Document".

So programs go by the extension. In our tests, LibreOffice opened sample-template.pot as a new untitled presentation and sample-template.ppt as an ordinary file, and the same bytes renamed from .ppt to .pot became a template. Renaming is therefore a real conversion for these binary files, unlike POTX and PPTX, where a content type inside the package has to change too.

• Create a presentation from it: double-click the .pot. PowerPoint opens a new, untitled presentation based on it.
• List it under File, New, Personal: move it to your personal templates folder, Documents\Custom Office Templates on Windows unless File, Options, Save sets another location.
• Edit the template itself: in PowerPoint, File, Open the .pot. Save it back as POT only if someone still uses PowerPoint 2003 or older.
• Convert it to POTX: File, Open the .pot, then File, Save As, **PowerPoint Template (*.potx), or PowerPoint Macro-Enabled Template (*.potm)** if it has macros you need.
• LibreOffice Impress opens a POT as a new untitled presentation, and saves one with File, Save As, PowerPoint 97–2003 Template.

Software that's translated with GNU gettext keeps a PO Template file named domainname.pot: a plain-text list of every translatable string in the program, made by the xgettext tool. Translators copy it to a .po file per language. Open-source projects often have dozens of them, so a .pot file in a source tree is usually a gettext file.

• To tell them apart, open the file in a text editor. Lines like msgid "Save" and msgstr "" mean gettext; unreadable characters starting with ÐÏ mean PowerPoint.
• gettext files are edited with a text editor or a translation tool such as Poedit, and processed with msginit, msgmerge and msgfmt. PowerPoint can't open them.
• The magic number decides: a PowerPoint POT starts with D0 CF 11 E0; a gettext POT is text, usually starting with # comments or msgid "".

Convert POT templates to POTX when you next edit them, or to POTM if they really need their macros. A POTX can't carry code.

• Double-clicking opens a new presentation, not the template. That's what templates do. Use File, Open in PowerPoint to change the template itself.
• New presentations open in Compatibility Mode. They can, when they come from an old-format template. Convert the template to POTX, or save the new presentation as PPTX.
• PowerPoint won't open it, or shows lines of msgid. It's a gettext translation template, not a PowerPoint file.
• Office blocks it. The Trust Center can block old binary file types (File, Options, Trust Center, File Block Settings), often by company policy.
• Videos in the template don't play. The binary format only links to videos; the video files have to travel with the template.
• My detector calls it a PPT. It's right about the contents. Only the extension marks a template.

• Convert to POTX with LibreOffice: soffice --headless --convert-to 'potx:Impress MS PowerPoint 2007 XML Template' old.pot, or --convert-to pptx for an ordinary presentation.
• Convert to PDF: soffice --headless --convert-to pdf old.pot, to see the example slides on any device.
• Keynote and Google Slides: Apple's list of files Keynote opens names PPTX, and Google's list of convertible files names PPT and PPTX. Rename a copy to .ppt, which is enough for these binary files, or convert it first.
• Look inside: Python's olefile lists the streams; Apache POI (HSLF) and LibreOffice read the masters and slides.
• In a browser: browsers can't display POT files, so a link to one downloads it.

A POT can hold VBA macros with nothing in its name to say so, and whatever a template contains is copied into every presentation made from it. Office blocks macros in files from the internet by default; the PPT page explains it. Other risks are the same as for PPT files:

• Action settings on master shapes or example slides that open web pages or start programs.
• Embedded OLE objects that run when activated.
• Parser bugs in the old binary reader, which has needed security fixes over the years. Keep Office updated and Protected View on.