/etc/issue.d/*
/run/issue.d/*
/usr/lib/issue.d/*
      The file /etc/issue is read from
      agetty(8)
      and similar tools and shown above the login prompt. While some of the
      informations can be adjusted with variables, the file itself is static. To
      display dynamic content,
      issue-generator(1)
      generates a /run/issue file from different files.
    
      Files in /etc/issue.d override files with the same
      name in /usr/lib/issue.d and
      /run/issue.d. Files in
      /run/issue.d override files with the same name in
      /usr/lib/issue.d. Packages should install their
      configuration files in /usr/lib/issue.d. Files in
      /etc/issue.d are reserved for the local
      administrator, who may use this logic to override the files installed by
      vendor packages. All configuration files are sorted by their filename
      in lexicographic order, regardless of which of the directories they reside in.