In an InDesign document when a font.status is SUBSTITUED, both the xmpTPg:Fonts/Resource/stFnt:versionString and also font.version property show the value of the font which is used by InDesign for the substitute font, and not the original (now missing) font version.

As anyone who has worked with font purchasing knows, the font version is extremely important. Both because of licensing reasons (previously purchased font licenses for font versions may need to be repurchased with newer versions), and also because even in a font produced by the same foundry or designer, a minor version change can include optical differences, spacing differences causing text reflow, overset text and glyph errors.

Here's an example

1) Open the attached document into Adobe InDesign
2) In the top dropdown menu, go to Type > Find/Replace Fonts
3) In the Find/Replace Fonts listing there is only one font and it is missing/substituted, SharpGroteskBook22
4) In the Find/Replace Fonts listing for the font in the “More Info” area the version is correctly shown as “Version 1.003”
5) However, when showing the properties of this font in Visual Studio Code Adobe Extendscript debugger the font.version for this font is incorrectly shown as: "version: 17.0d1e1" (see screenshot)
6) Also when viewing the metadata for the document in the File > File Info > Raw fonts xmpTPg:Fonts object, the versionString is incorrectly shown as “SharpGroteskBook2217.0d1e1” (see screenshot)

I am considering this behavior to be a bug.

In my opinion there is no value which is gained from InDesign having the font.version of a totally different font which is only being used to substitute a font which is not found.

Why does the font.version property not continue to return the value of the font when it was INSTALLED?

The data is not entirely missing. There is a location in InDesign which contains the accurate font version for a font which is font.status = SUBSTITUTED, and that is in the InDesign UI Fonts > Find/Replace Fonts menu, More Info area. I need a way to be able to retrieve that accurate data via scripting.

InDesign and InDesign Server versions 2023, 2022, 2020 etc.