The pkg-descr file in french/fr-med uses Latin-1 rather than UTF-8. Since UTF-8 locales are the commonly agreed standard these days, "pkg info fr-med" looks quite strange. As that port is also used outside the French community (FreeCAD relies on it), it would be nice to convert that file to UTF-8. (For that same reason, adding an English translation would be appreciated as well, but I could live with a French text if displayed correctly.)
You are right: when I created this port long time ago, it was only a dependency of french/aster, but nowadays Code_Aster has been localized, and these ports should be repo-moved to science (added in my TODO list). Fun fact: $ file /usr/ports/french/med/pkg-descr /usr/ports/french/med/pkg-descr: MED_Song
A commit references this bug: Author: thierry Date: Sun Jan 17 17:51:42 UTC 2021 New revision: 561843 URL: https://svnweb.freebsd.org/changeset/ports/561843 Log: Translate pkg-descr into english, thus removing Latin-1 encoding. PR: 252782 Submitted by: joerg Changes: head/french/med/pkg-descr