diff --git a/src/book/book.rs b/src/book/book.rs
index 54020362..6b6ce03b 100644
--- a/src/book/book.rs
+++ b/src/book/book.rs
@@ -8,11 +8,8 @@ use book::chapter::Chapter;
 pub struct Book {
     metadata: BookMetadata,
 
-    //preface: Vec<Chapter>,
     frontmatter: Vec<Chapter>,
-    //chapters: Vec<Chapter>,
     mainmatter: Vec<Chapter>,
-    //appendix: Vec<Chapter>,
     backmatter: Vec<Chapter>,
 }
 
diff --git a/src/book/chapter.rs b/src/book/chapter.rs
index db8ce3ea..7afb3610 100644
--- a/src/book/chapter.rs
+++ b/src/book/chapter.rs
@@ -1,24 +1,44 @@
-use std::path;
+use std::path::{Path, PathBuf};
+use book::metadata::Author;
 
 /// The Chapter struct holds the title of the chapter as written in the SUMMARY.md file,
 /// the location of the markdown file containing the content and eventually sub-chapters
+
+/// TODO use in template: author, description, index, class
+
 #[derive(Debug, Clone)]
 pub struct Chapter {
+    /// The title of the chapter.
     title: String,
-    file: path::PathBuf,
+    /// Path to chapter's markdown file.
+    file: PathBuf,
+
+    /// TODO The author of the chapter, or the book.
+    author: Author,
+    /// TODO The description of the chapter.
+    description: String,
+    /// TODO Index number of the chapter in its level. This is the Vec index + 1.
+    index: i32,
+    /// TODO CSS class that will be added to the page-level wrap div to allow customized chapter styles.
+    class: String,
 
     sub_chapters: Vec<Chapter>,
 }
 
-
 impl Chapter {
     /// Creates a new chapter with the given title and source file and no sub-chapters
-    pub fn new(title: &str, file: &path::Path) -> Self {
+    pub fn new(title: &str, file: &Path) -> Self {
         Chapter {
             title: title.to_owned(),
             file: file.to_owned(),
 
             sub_chapters: Vec::new(),
+
+            // TODO placeholder values for now
+            author: Author::new(""),
+            description: "".to_string(),
+            index: 0,
+            class: "".to_string(),
         }
     }
 
@@ -42,7 +62,7 @@ impl Chapter {
     pub fn title(&self) -> &str {
         &self.title
     }
-    pub fn file(&self) -> &path::Path {
+    pub fn file(&self) -> &Path {
         &self.file
     }
     pub fn sub_chapters(&self) -> &[Chapter] {
diff --git a/src/book/metadata.rs b/src/book/metadata.rs
index 0be79be7..6fe837cd 100644
--- a/src/book/metadata.rs
+++ b/src/book/metadata.rs
@@ -1,12 +1,32 @@
+use std::path::PathBuf;
+
+/// TODO use in template: subtitle, description, publisher, number_format, section_names
+
 #[derive(Debug, Clone)]
 pub struct BookMetadata {
+    /// The title of the book.
     pub title: String,
+
+    /// TODO The subtitle, when titles are in the form of "The Immense Journey: An
+    /// Imaginative Naturalist Explores the Mysteries of Man and Nature"
+    pub subtitle: String,
+
+    /// TODO A brief description or summary.
     pub description: String,
 
+    /// TODO Publisher's info
+    pub publisher: Publisher,
+
     pub language: Language,
 
     authors: Vec<Author>,
     translators: Vec<Author>,
+
+    /// TODO Chapter numbering scheme
+    number_format: NumberFormat,
+    /// TODO Section names for nested Vec<Chapter> structures, such as `[
+    /// "Part", "Chapter", "Section" ]`
+    section_names: Vec<String>,
 }
 
 #[derive(Debug, Clone)]
@@ -21,6 +41,38 @@ pub struct Language {
     code: String,
 }
 
+/// TODO use Publisher in template.
+
+#[derive(Debug, Clone)]
+pub struct Publisher {
+    name: String,
+    /// link to the sublisher's site
+    url: String,
+    /// path to publisher's logo image
+    logo_src: PathBuf,
+}
+
+impl Publisher {
+    pub fn default() -> Publisher {
+        Publisher {
+            name: "".to_string(),
+            url: "".to_string(),
+            logo_src: PathBuf::new(),
+        }
+    }
+}
+
+/// TODO use NumberFormat when rendering chapter titles.
+
+#[derive(Debug, Clone)]
+pub enum NumberFormat {
+    /// 19
+    Arabic,
+    /// XIX
+    Roman,
+    /// Nineteen
+    Word,
+}
 
 impl BookMetadata {
     pub fn new(title: &str) -> Self {
@@ -32,6 +84,12 @@ impl BookMetadata {
 
             authors: Vec::new(),
             translators: Vec::new(),
+
+            // TODO placeholder values for now
+            subtitle: "".to_string(),
+            publisher: Publisher::default(),
+            number_format: NumberFormat::Arabic,
+            section_names: vec![],
         }
     }