[Framers] White magic about Save as old version

[Klaus Daube]

   I have time for experiments ...

   I have set up an FM-14 document with text features introduced in
   various versions.

   Then I saved to an older FM-version using my script [1]Save FM document
   or book in older version

   I wanted to be certain whether the user gets strange messages when
   he/she opens the saved document in the older FM version.

   It turns out that everything works silently - there are no messages in
   the console log and no open messages.

   There seem to be a magic tag on these features for FM to be able to
   strip them out when saving to an older version. I assume this, because
   the file sizes differ:

   Original FM-14      73'728

   saved as FM-10      67'584

   saved as FM-09      68'608

   Until now I assumed that the "save as old" process just saves and
   indicates an old version and only the open process in the old
   FM-version skips unknown stuff - as it done with the MIFs.

   Is this a completely wrong assumption/interpretation of the process?

   If my findings are solid: It should be easy for Adobe to allow "Save as
   old" down to FM-8 similar to my script (Thats the Unidoce 'border').

   What is (might be) the reason to just save 'down' one version?

   The features in my FM-14 test file

   FM-9

      System variables

   FM-10

      Character background

      Poster for rich media

   FM-11

      Line numbers

   FM-12

      Paragraph property background

      QR code

      MathFlow from Desing Science

   FM-13

      MiniToc

      RTL Languages

      Conditionalised table columns

      Solid fill in table shading

   FM-14

      Nothing in this area



   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   ~~

   Klaus Daube             Phone:  +41-44-381 37 77

   Schäracher 11           Mail:   klaus at daube.ch

   CH-8053 Zürich          Web:    www.daube.ch

References

   1. file:///tmp/www.daube.ch/docu/fmaker73.html