A struck-through currency sign restricting use to non-commercial purposes.
The NC mark restricts use to purposes that are not primarily commercial. What counts as commercial is deliberately not defined precisely, which is the best-known difficulty with the condition rather than an oversight.
Restricts use of the work to purposes that are not primarily intended for or directed toward commercial advantage or monetary compensation.
Where the boundary of commercial use falls is not settled by the licence text, and the resulting uncertainty is why some projects avoid the condition entirely.
A circle outline containing a currency sign — a stroked S or a stroked e — crossed by a single diagonal bar.
Both are built from circles.