/usr/share/mime-info/scratch.keys is in scratch 1.4.0.6~dfsg1-5.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 | application/x-scratch-project
description: Scratch Application
[es]description: Aplicación de Scratch
icon_filename: scratch.png
default_action_type=application
short_list_application_ids_for_novice_user_level=scratch
short_list_application_ids_for_intermediate_user_level=scratch
short_list_application_ids_for_advanced_user_level=scratch
|