diff --git a/bookstore/src/main/java/com/fjordtek/bookstore/BookstoreApplication.java b/bookstore/src/main/java/com/fjordtek/bookstore/BookstoreApplication.java
index 1cdab98..f912da8 100644
--- a/bookstore/src/main/java/com/fjordtek/bookstore/BookstoreApplication.java
+++ b/bookstore/src/main/java/com/fjordtek/bookstore/BookstoreApplication.java
@@ -21,6 +21,15 @@ import com.fjordtek.bookstore.model.BookRepository;
 import com.fjordtek.bookstore.model.Category;
 import com.fjordtek.bookstore.model.CategoryRepository;
 
+/**
+*
+* This is the main Spring Boot application class for the bookstore project.
+* <p>
+* Initializes and handles initialization of the application.
+*
+* @author Pekka Helenius
+*/
+
 @SpringBootApplication
 public class BookstoreApplication extends SpringBootServletInitializer {
 	private static final Logger commonLogger = LoggerFactory.getLogger(BookstoreApplication.class);
diff --git a/bookstore/src/main/java/com/fjordtek/bookstore/model/Author.java b/bookstore/src/main/java/com/fjordtek/bookstore/model/Author.java
index da371e6..89c29bd 100644
--- a/bookstore/src/main/java/com/fjordtek/bookstore/model/Author.java
+++ b/bookstore/src/main/java/com/fjordtek/bookstore/model/Author.java
@@ -19,6 +19,16 @@ import javax.validation.constraints.Size;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
 
+/**
+ * This class implements Author entity which forms
+ * core structure for the corresponding AUTHOR table in a database.
+ * <p>
+ * Additionally, Author entity objects are Java objects having
+ * methods, attributes and other class-related additions within them.
+ *
+ * @author Pekka Helenius
+ */
+
 @Entity
 public class Author {
 
diff --git a/bookstore/src/main/java/com/fjordtek/bookstore/model/AuthorJsonSerializer.java b/bookstore/src/main/java/com/fjordtek/bookstore/model/AuthorJsonSerializer.java
index 399a267..f6b7d75 100644
--- a/bookstore/src/main/java/com/fjordtek/bookstore/model/AuthorJsonSerializer.java
+++ b/bookstore/src/main/java/com/fjordtek/bookstore/model/AuthorJsonSerializer.java
@@ -8,6 +8,20 @@ import com.fasterxml.jackson.core.JsonGenerator;
 import com.fasterxml.jackson.databind.SerializerProvider;
 import com.fasterxml.jackson.databind.ser.std.StdSerializer;
 
+/**
+ * This class implements Jackson JSON serializer for Author entity class.
+ * <p>
+ * When writing a JSON output based on a Author entity object, the processing
+ * is handled in the way described in this class.
+ * <p>
+ * Unless specifically instructed, customization defined in this class
+ * does not affect native Spring REST API JSON outputs generated
+ * by a controller having either @BasePathAwareController
+ * or @RepositoryRestController annotation.
+ *
+ * @author Pekka Helenius
+ */
+
 public class AuthorJsonSerializer extends StdSerializer<Author> {
 	private static final long serialVersionUID = 5233819344225306443L;
 
diff --git a/bookstore/src/main/java/com/fjordtek/bookstore/model/AuthorRepository.java b/bookstore/src/main/java/com/fjordtek/bookstore/model/AuthorRepository.java
index b6163ca..17a3af8 100644
--- a/bookstore/src/main/java/com/fjordtek/bookstore/model/AuthorRepository.java
+++ b/bookstore/src/main/java/com/fjordtek/bookstore/model/AuthorRepository.java
@@ -9,6 +9,13 @@ import org.springframework.data.repository.query.Param;
 import org.springframework.data.rest.core.annotation.RepositoryRestResource;
 import org.springframework.data.rest.core.annotation.RestResource;
 
+/**
+ * This interface extends CrudRepository interface, implementing
+ * custom methods for a repository containing Author entities.
+ *
+ * @author Pekka Helenius
+ */
+
 @RepositoryRestResource(
 		path            = "authors",
 		itemResourceRel = "authors",
diff --git a/bookstore/src/main/java/com/fjordtek/bookstore/model/Book.java b/bookstore/src/main/java/com/fjordtek/bookstore/model/Book.java
index dea04c3..010433f 100644
--- a/bookstore/src/main/java/com/fjordtek/bookstore/model/Book.java
+++ b/bookstore/src/main/java/com/fjordtek/bookstore/model/Book.java
@@ -33,6 +33,16 @@ import com.fasterxml.jackson.annotation.JsonUnwrapped;
 import com.fasterxml.jackson.databind.annotation.JsonSerialize;
 import com.fjordtek.bookstore.annotation.CurrentYear;
 
+/**
+ * This class implements Book entity which forms
+ * core structure for the corresponding BOOK table in a database.
+ * <p>
+ * Additionally, Book entity objects are Java objects having
+ * methods, attributes and other class-related additions within them.
+ *
+ * @author Pekka Helenius
+ */
+
 @Entity
 public class Book {
 
diff --git a/bookstore/src/main/java/com/fjordtek/bookstore/model/BookEventHandler.java b/bookstore/src/main/java/com/fjordtek/bookstore/model/BookEventHandler.java
index 6feba42..bcdeaff 100644
--- a/bookstore/src/main/java/com/fjordtek/bookstore/model/BookEventHandler.java
+++ b/bookstore/src/main/java/com/fjordtek/bookstore/model/BookEventHandler.java
@@ -7,6 +7,22 @@ import org.springframework.data.rest.core.annotation.HandleAfterCreate;
 import org.springframework.data.rest.core.annotation.RepositoryEventHandler;
 import org.springframework.stereotype.Component;
 
+/**
+ * This class is part of Spring framework, having @Component
+ * annotation.
+ * <p>
+ * The class implements @RepositoryEventHandler annotation
+ * for Book class which instructs Spring to use custom method
+ * implementations for events annotated with specific event
+ * handlers in the class.
+ *
+ * @see https://docs.spring.io/spring-data/rest/docs/current/reference/html/#events
+ * @see https://stackoverflow.com/questions/49504103/override-spring-data-rest-post-method
+ * @see https://www.baeldung.com/spring-data-rest-events
+ *
+ * @author Pekka Helenius
+ */
+
 @Component
 @RepositoryEventHandler(Book.class)
 public class BookEventHandler {
@@ -22,9 +38,6 @@ public class BookEventHandler {
 	 *     curl --request POST --header "Content-Type: application/json" --data
 	 *     '{"title":"Bloody Chamber", ...}' http://localhost:8080/api/booklist
 	 *
-	 * Ref: https://docs.spring.io/spring-data/rest/docs/current/reference/html/#events
-	 *      https://stackoverflow.com/questions/49504103/override-spring-data-rest-post-method
-	 *      https://www.baeldung.com/spring-data-rest-events
 	 */
 	@HandleAfterCreate
 	public void handleAfterCreate(Book book) {
diff --git a/bookstore/src/main/java/com/fjordtek/bookstore/model/BookHash.java b/bookstore/src/main/java/com/fjordtek/bookstore/model/BookHash.java
index 4fc222c..6e6bec1 100644
--- a/bookstore/src/main/java/com/fjordtek/bookstore/model/BookHash.java
+++ b/bookstore/src/main/java/com/fjordtek/bookstore/model/BookHash.java
@@ -19,19 +19,27 @@ import org.hibernate.annotations.Parameter;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
 
-/*
+/**
+ * This class implements BookHash entity which forms
+ * core structure for the corresponding BOOK_HASH table in a database.
+ * <p>
+ * Additionally, BookHash entity objects are Java objects having
+ * methods, attributes and other class-related additions within them.
+ * <p>
  * This entity shares same primary key with the Book entity
  * which is simultaneously a foreign key (unidirectional mapping)
  * for this one.
- * For implementation reference, see also:
- * https://www.programmersought.com/article/1610322983/
- *
+ * <p>
  * This entity generates a table which holds auto-generated
  * random string values associated to each book.
- *
+ * <p>
  * These random string values represent difficult-to-enumerate
  * unique book IDs used for front-end purposes. Main purpose
  * is not to expose real Book entity id value.
+ *
+ * @see https://www.programmersought.com/article/1610322983/
+ *
+ * @author Pekka Helenius
  */
 
 @Entity
diff --git a/bookstore/src/main/java/com/fjordtek/bookstore/model/BookHashRepository.java b/bookstore/src/main/java/com/fjordtek/bookstore/model/BookHashRepository.java
index 1f552e7..301df54 100644
--- a/bookstore/src/main/java/com/fjordtek/bookstore/model/BookHashRepository.java
+++ b/bookstore/src/main/java/com/fjordtek/bookstore/model/BookHashRepository.java
@@ -8,6 +8,13 @@ import org.springframework.data.repository.CrudRepository;
 import org.springframework.data.repository.query.Param;
 import org.springframework.data.rest.core.annotation.RepositoryRestResource;
 
+/**
+ * This interface extends CrudRepository interface, implementing
+ * custom methods for a repository containing BookHash entities.
+ *
+ * @author Pekka Helenius
+ */
+
 @RepositoryRestResource(
 		path            = "bookhashes",
 		itemResourceRel = "bookhashes",
diff --git a/bookstore/src/main/java/com/fjordtek/bookstore/model/BookRepository.java b/bookstore/src/main/java/com/fjordtek/bookstore/model/BookRepository.java
index 145c8b1..f93df03 100644
--- a/bookstore/src/main/java/com/fjordtek/bookstore/model/BookRepository.java
+++ b/bookstore/src/main/java/com/fjordtek/bookstore/model/BookRepository.java
@@ -12,6 +12,13 @@ import org.springframework.data.repository.query.Param;
 import org.springframework.data.rest.core.annotation.RepositoryRestResource;
 import org.springframework.data.rest.core.annotation.RestResource;
 
+/**
+ * This interface extends CrudRepository interface, implementing
+ * custom methods for a repository containing Book entities.
+ *
+ * @author Pekka Helenius
+ */
+
 @RepositoryRestResource(
 		path            = "booklist",
 		itemResourceRel = "booklist",
diff --git a/bookstore/src/main/java/com/fjordtek/bookstore/model/Category.java b/bookstore/src/main/java/com/fjordtek/bookstore/model/Category.java
index b3ab1d9..b948867 100644
--- a/bookstore/src/main/java/com/fjordtek/bookstore/model/Category.java
+++ b/bookstore/src/main/java/com/fjordtek/bookstore/model/Category.java
@@ -16,6 +16,16 @@ import javax.persistence.SequenceGenerator;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
 
+/**
+ * This class implements Category entity which forms
+ * core structure for the corresponding CATEGORY table in a database.
+ * <p>
+ * Additionally, Category entity objects are Java objects having
+ * methods, attributes and other class-related additions within them.
+ *
+ * @author Pekka Helenius
+ */
+
 @Entity
 public class Category {
 
diff --git a/bookstore/src/main/java/com/fjordtek/bookstore/model/CategoryJsonSerializer.java b/bookstore/src/main/java/com/fjordtek/bookstore/model/CategoryJsonSerializer.java
index d7c71c0..f6faf5a 100644
--- a/bookstore/src/main/java/com/fjordtek/bookstore/model/CategoryJsonSerializer.java
+++ b/bookstore/src/main/java/com/fjordtek/bookstore/model/CategoryJsonSerializer.java
@@ -8,6 +8,20 @@ import com.fasterxml.jackson.core.JsonGenerator;
 import com.fasterxml.jackson.databind.SerializerProvider;
 import com.fasterxml.jackson.databind.ser.std.StdSerializer;
 
+/**
+ * This class implements Jackson JSON serializer for Category entity class.
+ * <p>
+ * When writing a JSON output based on a Category entity object, the processing
+ * is handled in the way described in this class.
+ * <p>
+ * Unless specifically instructed, customization defined in this class
+ * does not affect native Spring REST API JSON outputs generated
+ * by a controller having either @BasePathAwareController
+ * or @RepositoryRestController annotation.
+ *
+ * @author Pekka Helenius
+ */
+
 public class CategoryJsonSerializer extends StdSerializer<Category> {
 	private static final long serialVersionUID = 6376700470881235634L;
 
diff --git a/bookstore/src/main/java/com/fjordtek/bookstore/model/CategoryRepository.java b/bookstore/src/main/java/com/fjordtek/bookstore/model/CategoryRepository.java
index 21037bc..0f41411 100644
--- a/bookstore/src/main/java/com/fjordtek/bookstore/model/CategoryRepository.java
+++ b/bookstore/src/main/java/com/fjordtek/bookstore/model/CategoryRepository.java
@@ -9,6 +9,13 @@ import org.springframework.data.repository.query.Param;
 import org.springframework.data.rest.core.annotation.RepositoryRestResource;
 import org.springframework.data.rest.core.annotation.RestResource;
 
+/**
+ * This interface extends CrudRepository interface, implementing
+ * custom methods for a repository containing Category entities.
+ *
+ * @author Pekka Helenius
+ */
+
 @RepositoryRestResource(
 		path            = "categories",
 		itemResourceRel = "categories",
diff --git a/bookstore/src/main/java/com/fjordtek/bookstore/web/BigDecimalPropertyEditor.java b/bookstore/src/main/java/com/fjordtek/bookstore/web/BigDecimalPropertyEditor.java
index 7f7a7b4..0f2b47d 100644
--- a/bookstore/src/main/java/com/fjordtek/bookstore/web/BigDecimalPropertyEditor.java
+++ b/bookstore/src/main/java/com/fjordtek/bookstore/web/BigDecimalPropertyEditor.java
@@ -5,6 +5,12 @@ package com.fjordtek.bookstore.web;
 import java.beans.PropertyEditorSupport;
 import java.math.BigDecimal;
 
+/**
+ * Converts numbers with custom decimal separators to proper BigDecimal format.
+ *
+ * @author Pekka Helenius
+ */
+
 public class BigDecimalPropertyEditor extends PropertyEditorSupport {
 
 	@Override
diff --git a/bookstore/src/main/java/com/fjordtek/bookstore/web/BookRestController.java b/bookstore/src/main/java/com/fjordtek/bookstore/web/BookRestController.java
index 43a7778..826041e 100644
--- a/bookstore/src/main/java/com/fjordtek/bookstore/web/BookRestController.java
+++ b/bookstore/src/main/java/com/fjordtek/bookstore/web/BookRestController.java
@@ -20,6 +20,15 @@ import com.fjordtek.bookstore.model.Book;
 import com.fjordtek.bookstore.model.BookHashRepository;
 import com.fjordtek.bookstore.model.BookRepository;
 
+/**
+*
+* This class implements a custom JSON-related controller for the bookstore,
+* handling requests to a predetermined end points only, using a special prefix
+* value in its hard-coded @RequestMapping annotation.
+*
+* @author Pekka Helenius
+*/
+
 @RestController
 @RequestMapping("json")
 public class BookRestController {
diff --git a/bookstore/src/main/java/com/fjordtek/bookstore/web/HttpServerLogger.java b/bookstore/src/main/java/com/fjordtek/bookstore/web/HttpServerLogger.java
index af01882..07b4e1b 100644
--- a/bookstore/src/main/java/com/fjordtek/bookstore/web/HttpServerLogger.java
+++ b/bookstore/src/main/java/com/fjordtek/bookstore/web/HttpServerLogger.java
@@ -12,6 +12,13 @@ import javax.servlet.http.HttpServletResponse;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+/**
+*
+* This class implements a custom logger for HTTP requests.
+*
+* @author Pekka Helenius
+*/
+
 public class HttpServerLogger {
 
 	private static final Logger serverLogger = LoggerFactory.getLogger(HttpServerLogger.class);