18 CFR §1301.68

1. (a)Classified information shall be marked pursuant to the standards set forth in section 1.6, Identification and Marking, of the Executive Order; Information Security Oversight Office implementing directives in 32 CFR part 2001, subpart B; and internal TVA procedures.
2. (b)Foreign government information shall retain its original classification markings or be marked and classified at a U.S. classification level that provides a degree of protection at least equivalent to that required by the entity that furnished the information. Foreign government information retaining its original classification markings need not be assigned a U.S. classification marking provided the responsible agency determines that the foreign government markings are adequate to meet the purposes served by U.S. classification markings.
3. (c)Information assigned a level of classification under predecessor executive orders shall be considered as classified at that level of classification.