The same idea, and only one of them has any legal force.
Both stand for permissions being passed on: anything built on the work carries the same freedoms. The share-alike mark is an actual licence condition and binds. The copyleft symbol is a reversed C that names the concept, is registered nowhere, and imposes nothing — a work is copyleft because of the licence it carries, not because of that badge.
The copyleft C is a concept with no legal force of its own; the share-alike mark is a specific licence condition that does have one.
Drawn from the visual attributes recorded for each symbol. Only traits the two records disagree about are listed.
| Trait | Share-alike mark (SA) | Copyleft symbol |
|---|---|---|
| Built from | circles and arrows | circles and letter like |
| Orientation | upright | mirrored |
| Share-alike mark (SA) | Copyleft symbol | |
|---|---|---|
| Legally binding | Yes, as a licence condition | No |
| Registered | Published by Creative Commons | Nowhere |
| What makes a work copyleft | This condition | The licence, not this symbol |
| Shape | A looping arrow in a circle | A reversed C in a circle |
| Relationship (from Symbolwise's records) | Commonly confused with Copyleft symbol — The copyleft C is a concept with no legal force of its own; the share-alike mark is a specific licence condition that does have one. | Commonly confused with Share-alike mark (SA) — The share-alike condition is the licensing term that actually imposes copyleft; this symbol only names the idea. |
Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
Creative Commons · retrieved 2026-08-01
The issuing body's own published deed. Authoritative for what the licence permits and requires, and for the mark that denotes it. It is not legal advice, and it says nothing about whether a given work is validly licensed — only what the licence means if it is.
Wikipedia · retrieved 2026-08-01
Tertiary reference. Used for identity, origin and current use, not for the legal effect of any licence — that is taken from the issuing body's own deed.
Wikipedia · retrieved 2026-08-01
Tertiary reference. Used for identity, origin and current use, not for the legal effect of any licence — that is taken from the issuing body's own deed.
Wikipedia · retrieved 2026-08-01
Tertiary reference. Used for identity, origin and current use, not for the legal effect of any licence — that is taken from the issuing body's own deed.
The contactless indicator is four nested arcs and marks a payment card or terminal. The N-Mark is a wave-like capital N, is a trademark of the NFC Forum, and marks where to tap a device for near-field communication generally. The underlying radio technology overlaps, which is why the two get used interchangeably even though the marks belong to different bodies.
Both are drawn as arcs radiating from a point, which is why they are confused. The Wi-Fi mark fans upward from a dot at the base and indicates a wireless network. The contactless mark lies on its side, opening to the right, and indicates that a card or terminal supports tap payment. Orientation is the reliable tell.
A single C in a circle asserts copyright. Two C shapes mark a Creative Commons licence — which grants specific permissions while the creator keeps their copyright. A CC badge does not put a work in the public domain, and it does not tell you what you may do on its own: the condition marks beside it carry the terms.
© covers creative works and generally applies automatically on creation. ™ and ® both cover brand marks, but ™ asserts an unregistered claim anyone may use, while ® is legally restricted to marks actually registered with a trademark office — using ® without registration is unlawful in many jurisdictions.