Sub-series consists of the main register kept by Ottawa to list the C.I.28 certificates issued either to replace destroyed or lost identifying certificates (C.I.5, C.I.30 and C.I.36), or to identify "native-born" persons without such certificates. The register covers C.I.28 certificates nos. 1-14353 (nos. 1-20 being un-issued samples, 24 January 1912 to 19 July 1947).
The entries are in numerical order, corresponding to a rough chronological order by date of issue. Each entry gives: the C.I.28 number; the person's name; his/her port, ship and date of arrival in Canada; his/her "serial number" (the Ottawa serial number, indicating the location of the person's entry in the General Registers, above); numbers of C.I.4 and C.I.5 certificates issued; file number of relevant case file (first CR series); date of issue of C.I.28 and Remarks, usually a residence address, name used on arrival in Canada (if different from current name), and notes on undocumented arrivals.
Most of the persons listed in this register arrived in Canada at Vancouver or Victoria after 1890, but there are some arrivals through other ports (notably Sarnia, 1895-1905) and some dated as early as the 1870's.