I picked up a volume of the Dictionary of Literary Biography to look at for classification, because I've got them with the literary criticism but haven't relabeled them from collected biography. Then I looked at OCLC's Classify service to survey how others have classified them, and at the WebDewey reference service to confirm [© 2012 OCLC. Domestic and international trademarks and/or service marks of OCLC Online Computer Library Center, Inc. and its affiliates]. The Notes for Table 3B have the following (sometimes OCLC cracks me up):
So when we get one of those (a collection of 19th-century fiction of several literatures about urban life) I'll print the labelSometimes aspects low in the priority listings can be expressed only by means of standard subdivision notation from Table 1. In the example above of a critical appraisal of later-20th-century American fiction about ocean travel by women, use notation T1--082 from Table 1 to express the aspect of women: 813.540932162082. For another example, use 808.83935820973209034 for a collection of 19th-century fiction of several literatures about urban life: 808.839 (collection of fiction from more than two literatures displaying specific features) + T3C--358209732 (theme: urban life) + T1--09034 (standard subdivision for the historical period of the 19th century). In the priority listing, theme comes before period; and once the theme has been expressed, there is no way to express the period except by use of the standard subdivision.
so that perhaps the numbers will retain their meaning for me, if no one else. School Library Journal and my state-level librarians' listserv about both talking about the future for the Dewey Decimal Classification system in schools. I'm not ready to ditch it, but it does seem rather complex sometimes. I suppose that's what happens when one tries to systematically classify all human knowledge.808.83935820973209034