Mulberry Symbols by Steve Lee are licensed under Creative Commons Attribution-ShareAlike 4.0.
https://mulberrysymbols.org/
https://creativecommons.org/licenses/by-sa/4.0/
PNG conversion and resizing: AAC Pages draft, same CC BY-SA 4.0.
Exact upstream SVG source links and source hashes: /licenses/mulberry-workflow-symbols.json.
Rendered PNG symbols remain freely available at /art/buttons/ under the same CC BY-SA 4.0 license. Original SVGs are retained in the downloadable source/review backups, not duplicated in the website deployment.
No charge for symbols and no additional restrictions. Other existing artwork retains its existing licenses.