The groups categorize the topics or contents of a work into one of the following:
Dewey Decimal Classification System
(From DDC 23)
000 – General works, Computer science and Information
100 – Philosophy and psychology
200 – Religion
300 – Social sciences
400 – Language
500 – Science
600 – Technology
700 – Arts & recreation
800 – Literature
900 – History & geography
The classes are further broken down to specify specific topics. For example, looking at just the 200's where religion is gathered, it breaks down like this -
200 RELIGION
201 Religious mythology, general classes of religion, interreligious relations and attitudes, social theology
202 Doctrines
203 Public worship and other practices
204 Religious experience, life, practice
205 Religious ethics
206 Leaders and organization
207 Missions and religious education
208 Sources
209 Sects and reform movements
210 Natural theology
211 Concepts of God
212 Existence, attributes of God
213 Creation
214 Theodicy
215 Science & religion
216 No longer used—formerly Evil
217 No longer used—formerly Prayer
218 Humankind
219 No longer used—formerly Analogies
220 Bible
221 Old Testament
222 Historical books of Old Testament
223 Poetic books of Old Testament
224 Prophetic books of Old Testament
225 New Testament
226 Gospels & Acts
227 Epistles
228 Revelation (Apocalypse)
229 Apocrypha & pseudepigrapha
230 Christian theology
231 God
232 Jesus Christ & his family
233 Humankind
234 Salvation (Soteriology) & grace
235 Spiritual beings
236 Eschatology
237 No longer used—formerly Future state
238 Creeds & catechisms
239 Apologetics & polemics
240 Christian moral & devotional theology
241 Moral theology
242 Devotional literature
243 Evangelistic writings for individuals
244 No longer used—formerly Religious fiction
245 No longer used—formerly Hymnology
246 Use of art in Christianity
247 Church furnishings & articles
248 Christian experience, practice, life
249 Christian observances in family life
250 Christian orders & local church
251 Preaching (Homiletics)
252 Texts of sermons
253 Pastoral office (Pastoral theology)
254 Parish government & administration
255 Religious congregations & orders
256 No longer used—formerly Religious societies
257 No longer used—formerly Parochial schools, libraries, etc.
258 No longer used—formerly Parochial medicine
259 Activities of the local church
260 Christian social theology
261 Social theology
262 Ecclesiology
263 Times, places of religious observance
264 Public worship
265 Sacraments, other rites & acts
266 Missions
267 Associations for religious work
268 Religious education
269 Spiritual renewal
270 Christian church history
271 Religious orders in church history
272 Persecutions in church history
273 Heresies in church history
274 Christian church in Europe
275 Christian church in Asia
276 Christian church in Africa
277 Christian church in North America
278 Christian church in South America
279 Christian church in other areas
280 Christian denominations & sects
281 Early church & Eastern churches
282 Roman Catholic Church
283 Anglican churches
284 Protestants of Continental origin
285 Presbyterian, Reformed, Congregational
286 Baptist, Disciples of Christ, Adventist
287 Methodist & related churches
288 No longer used—formerly Unitarian
289 Other denominations & sects
290 Other & comparative religions
291 Comparative religion
292 Classical (Greek & Roman) religion
293 Germanic religion
294 Religions of Indian origin
295 Zoroastrianism (Mazdaism, Parseeism)
296 Judaism
297 Islam, Bábism & Bahá'í Faith
298 No longer used—formerly Mormonism
299 Other religions