Since sometime during the life of DDC 18 (published 1971), there have been two different standard period tables at 810.1-818 Subdivisions of American literature in English:
(1) For Canada;
(2) For literature in English language from any part of North America, South America, Hawaii, and geographically associated islands; for comprehensive works on literature in English language from all these areas.
The Library of Congress (LC) has applied the Canadian period table for Canadian literature without using any initial letter to distinguish Canadian literature. Library and Archives Canada (LAC) has used the period table for Canada with “C” to indicate Canada, e.g., C813.3 Canadian fiction in English of colonial period to 1867 for St. Ursula's Convent, or, The Nun of Canada and C813.54 Canadian Fiction in English, 1945–1999 for The Handmaid's Tale. See “LAC Dewey Decimal Classification Policy.”
Plans to create separate MARC 21 records for each number in a literary period table drew our attention to the anomaly of two standard period tables. To eliminate that anomaly, the period table for Canadian literature in English has been changed to optional—like the optional period table for Canadian literature in French at 840.1-848 Subdivisions of French literature. The notation in the period table for Canadian literature in English remains unchanged.
LAC continues to use the period table for Canada with “C” to indicate Canada. LC no longer uses the special table for Canada; instead, LC is now applying the standard table for literature in English language from any part of North America to Canadian literature in English. Few authors are affected by the change: the two tables are exactly the same for the 20th and 21st centuries. Only a few Canadian authors are affected by discrepancies in earlier periods—primarily those who began to flourish before 1830 (including Julia Catherine Beckwith Hart, the author of St. Ursula's Convent; her standard number is now 813.2 American fiction in English, 1776-1829).