Creative Commons licenses
30-second summary. Every CC license requires attribution (BY). Optional elements: NC NonCommercial, SA ShareAlike, ND NoDerivatives. For OER, prefer CC BY or CC BY-SA. Licenses are irrevocable for copies already released.
The four elements
| Code | Name | Meaning |
|---|---|---|
| BY | Attribution | Credit the creator, source and license; indicate changes |
| SA | ShareAlike | Adaptations must use the same (or a compatible) license |
| NC | NonCommercial | No use primarily intended for commercial advantage |
| ND | NoDerivatives | Adapted versions may not be shared |
Six licenses (4.0) and CC0 — most to least open
| License | Reuse | Adapt/remix | Commercial | OER? |
|---|---|---|---|---|
| CC0 1.0 waiver | ✓ | ✓ | ✓ | ✓ |
| CC BY 4.0 | ✓ | ✓ | ✓ | ✓ |
| CC BY-SA 4.0 | ✓ | ✓ (keep BY-SA) | ✓ | ✓ |
| CC BY-NC 4.0 | ✓ | ✓ | ✗ | ✓ (limited) |
| CC BY-NC-SA 4.0 | ✓ | ✓ (keep BY-NC-SA) | ✗ | ✓ (limited) |
| CC BY-ND 4.0 | ✓ | ✗ | ✓ | Not full 5R |
| CC BY-NC-ND 4.0 | ✓ | ✗ | ✗ | Not full 5R |
Choosing
- Widest possible use, including publishers and commercial platforms → CC BY.
- Every improvement must stay open → CC BY-SA (as Wikipedia).
- No resale → CC BY-NC-SA — but "commercial" is hard to define (tutoring centres, private schools), and NC blocks remixing with BY-SA.
- No edits at all → reconsider: ND materials are not fully OER.
Official tool: CC License Chooser.
Remix compatibility
| A \ B | CC0 / BY | BY-SA | BY-NC | BY-NC-SA | any ND |
|---|---|---|---|---|---|
| CC0 / BY | ✓ | ✓ → BY-SA | ✓ → BY-NC | ✓ → BY-NC-SA | ✗ |
| BY-SA | ✓ → BY-SA | ✓ → BY-SA | ✗ | ✗ | ✗ |
| BY-NC | ✓ → BY-NC | ✗ | ✓ → BY-NC | ✓ → BY-NC-SA | ✗ |
| BY-NC-SA | ✓ → BY-NC-SA | ✗ | ✓ → BY-NC-SA | ✓ → BY-NC-SA | ✗ |
✗ = cannot be released together under one license, though works may sit side by side in a collection, each with its own license.
Common misconceptions
- Adding your own restrictions to a CC license. Don't: terms that restrict the rights the license grants mean it is no longer a standard CC license and confuse users (CC FAQ). Pick a more restrictive CC license instead.
- Revoking a license. Copies already released stay usable under that license.
- CC replaces copyright. No — CC licenses rely on copyright; creators keep it and grant permissions in advance.
- Classroom exceptions are enough. Statutory exceptions under Vietnam's IP Law are narrow; a CC license is clearer and broader.
Next: Attribution & reuse →