5.35.1 Element information
5.35.2 RDA definition and scope
126.96.36.199 A timespan associated with a claim of protection under copyright or a similar regime.
188.8.131.52 A copyright date includes a phonogram date associated with a claim of protection for an audio recording.
5.35.3 General rule
184.108.40.206 If a Date of publication does not appear on the manifestation and it is likely that the date of copyright or deposit represents the Date of publication, supply the date in square brackets as the Date of publication (see 220.127.116.11). Always indicate the copyright date as the basis for the conjecture in a Note on publication statement (see 18.104.22.168).
Date of publication: 
Note on publication statement: Date of publication based on copyright date. Copyright statement on title page verso reads: Entered according to Act of Congress, in the year 1866, by J.R. Jones, in the Clerk’s Office of the District Court of the United States, in and for the Eastern District of Pennsylvania
22.214.171.124 If a Date of publication does not appear on the manifestation, and the date of copyright or deposit does not represent the probable date of publication, record it nonetheless in Copyright date, and supply a more accurate date of publication in square brackets (see 126.96.36.199). Provide an explanation for the supplied date in a Note on copyright date (see 188.8.131.52).