Manifest Markings & Verification of Naturalizations

In 1926 verification clerks began to record the verification (record check) and naturalization certification activity on each passenger list record. The
annotations may be found on any passenger list, before or after 1926, but they all relate to naturalization activity occurring in 1926 or later.

You can read about Manifest Markings and their meanings (plus refer to a District Number decoder) at
http://www.jewishgen.org/InfoFiles/Manifests/occ/

For a Resource Guide and links to online Naturalization records, what you can expect to find, where to find them, and alternate sources of finding those important years (immigration and naturalization) at
http://naturalizationrecords.com/usa/