4.0/Attribution and marking
Attribution has been a standard feature of all CC licenses since the version 2.0 suite. Currently, the requirements for attributing works are primarily  contained in Section 4 of the 3.0 license legal code. These provisions require users of a work to implement the following in any reasonable manner: :
- keep copyright notices intact; and
- reasonable to the medium or means used by the licensee,
- provide the name the original author (or her pseudonym, or other attribution party, when provided);
- provide the title of the work if supplied;
- include the URI associated with the work (if it refers to the copyright notice or licensing information); and
- where an adaptation is created (when permitted by the license), include a credit stating that the work has been used in the adaptation  , and label clearly that changes were made to the work. 
All 3.0 licenses allow licensors to request removal of the credit when their works are reproduced in a collection, as well as when their works are adapted (where permitted by the licenses). Specifically, all six version 3.0 licenses provide: 
- If You create a Collection, upon notice from any Licensor You must, to the extent practicable, remove from the Collection any credit as required by Section 4(__), as requested.
And in BY, BY-SA, BY-NC-SA, and BY-NC, additionally:
- If You create an Adaptation, upon notice from any Licensor You must, to the extent practicable, remove from the Adaptation any credit as required by Section 4(__), as requested. 
The attribution requirement is reflected on the CC deeds as:
- Attribution – You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work).
A few legal decisions have successfully enforced the attribution requirement.
The attribution requirements have drawn some criticism, including:
- General difficulty understanding what is required on the part of licensees, in part due to the “reasonable to the medium or means” language.
- Absence of a mechanism for requesting or permitting removal of a credit for reproductions of an unmodified work when not reproduced as part of a collection.
Note: For issues and proposals relating to attribution requirements of adaptations, please see the 4.0/Treatment of adaptations of adaptations page.
Proposals for 4.0
[Note: these proposals are not necessarily mutually exclusive]
- Consolidate the attribution requirements into a single location within the licenses (e.g., Section 4), including all other marking requirements such as providing the URI for the license.
- Other comments:
- Expand the existing mechanism for requesting removal of the attribution credit so licensors can request removal for any reuse.
- Other comments:
- Create a mechanism in the license allowing licensors to waive attribution completely.
- Other comments:
We encourage you to sign up for the license discussion mailing list, where we will be debating this and other 4.0 proposals. HQ will provide links to related email threads from the license discussion mailing list here.
Please add citations that ought inform this 4.0 issue below.
- See Section 3(b) of CC BY 3.0 wherein the obligation to clearly label a work as a derivative is contained.
- See the Marking Page for further information.
- Per Section 4(b) of CC BY 3.0, In the case of an adaptation or collection, where a credit for all contributing authors appears, the credit required must be at least as prominent as the credits for other contributing authors.
- This obligation is contained in Section 3(b) of those licenses that permit adaptations to be made.
- This is found in Section 4(a) in each of the six licenses.
- This is found in Section 4(a) in each of the four noted version 3.0 licenses.
- Although, a licensor may always enter into a separate agreement with licensees to have attribution waived.