PubIt! ePub Formatting Guide
Contents:
I.
II.
III.
IV.
V.
VI.
VII.
VIII.
IX.
X.
XI.
Introduction
What is ePub?
ePub requirements
OPF specifications
NCX listing
Image optimization
Files
CSS/Fonts
Special Characters
General eBook Conventions
Appendix A
I.
Introduction
ePub is an open source, industry standard format for eBooks. Barnes & Noble sells digital content that is
in the ePub format. Because ePub is reflowable, customers can read files that are formatted in ePub on
the NOOK dedicated eReading device and on iPad, iPhone/iPod touch, Android, and PC via Barnes &
Noble’s free NOOK eReading software.
Publishers looking to sell highly formatted eBooks should convert their eBooks to ePub before uploading
them via PubIt! to ensure optimum formatting.
In this document, we provide background information on the ePub format and guidelines for optimizing
your ePub to render well across the NOOK line of eReading products.
II.
What is ePub?
As defined by the International Digital Publishing Forum (IDPF),
".epub" is the file extension of an XML format for reflowable digital books and
publications. ".epub" is composed of three open standards, the Open
Publication Structure (OPS), Open Packaging Format (OPF) and Open Container
Format (OCF), produced by the IDPF.
More information on the ePub standard is available at the following websites:
•
•
•
http://www.openebook.org/2007/ops/OPS_2.0_final_spec.html
http://www.openebook.org/2007/opf/OPF_2.0_final_spec.html
http://www.idpf.org/ocf/ocf1.0/download/ocf10.htm
Publishers not familiar with the ePub specification should follow the above links to learn more about the
file format and container requirements.
Copyright ©2010, Barnes & Noble
III.
ePub Requirements
ePubs are essentially “zip” files with a different extension. By renaming the file name of an ePub from
“xyz.epub” to “xyz.zip”, it can be zipped, unzipped, etc.
There are three fixed elements to every ePub file:
1. MIMETYPE file
2. META-INF folder
3. OEBPS folder
The MIMETYPE file occurs at the root level; both the META-INF and OEBPS folders occur below that. All
other files can be organized as works best for the publisher. Two required files are CONTENT.OPF and
TOC.NCX.
ePubs should be validated using EPUBCHECK (the latest version as of this writing is 1.0.5), available at
http://code.google.com/p/epubcheck/. Documentation is forthcoming, but you can either open the
ReadMe file or visit here for instruction on how to use it:
http://code.google.com/p/epubcheck/wiki/Running.
IV.
OPF specifications
The basic OPF file contains metadata statements, a manifest of included files, and a list of the “playing”
order of the files. While additional information can be supplied in the OPF that controls the behavior of
other ebook readers, this is not a requirement for nook.
Metadata – The metadata starts with these three required lines of code. Note the unique-identifier
declared in the second statement -- this should represent a unique identifier scheme in use in your
organization.
•
•
•
<?xml version="1.0" encoding="UTF-8" ?>
<package version="2.0" unique-identifier="PrimaryID" xmlns="http://www.idpf.org/2007/opf">
<metadata xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:opf="http://www.idpf.org/2007/opf">
Barnes & Noble requires these statements:
TITLE <dc:title>title</dc:title>
AUTHOR <dc:creator>author name</dc:creator>
PUBLISHER <dc:publisher>publisher name</dc:publisher>
PUB DATE <dc:date>date</dc:date>
ID <dc:identifier id="PrimaryID">identification code</dc:identifier>
LANGUAGE <dc:language>en</dc:language>
Barnes & Noble does not currently require a unique metadata statement defining a cover.
Manifest – The manifest identifies every file contained in the epub – if a file is not identified, it will not
be accessible. Example of different file statements:
Copyright ©2010, Barnes & Noble
•
<item id="pt" href="my_page.xpgt" media-type="application/vnd.adobe-pagetemplate+xml"/>
• <item id="style" href="mystyle.css" media-type="text/css" />
• <item id="image001" href="image001.jpg" media-type="image/jpeg" />
• <item id="image002" href="image002.png" media-type="image/png" />
• <item id="cover" href="cover_page.xhtml" media-type="application/xhtml+xml" />
• <item id="toc" href="content_page.xhtml" media-type="application/xhtml+xml" />
• <item id="ncx" href="toc.ncx" media-type="application/x-dtbncx+xml" />
Note that item id "toc" refers to the physical contents page while item id "ncx" refers to the file that
controls ebook navigation.
Spine – the spine controls the playing order of the ebook and determines which file precedes/follows
another.
Guide – the guide is a list of references defining structural elements of the ebook (TOC, List of
Illustrations, Index, Copyright, etc). Use of guide elements is optional for nook.
V.
NCX specifications
The NCX file contains the hierarchical table of contents and is represented by the Navigation Panel in
Adobe Digital Editions. The listings in the NCX file are visible under the “Go To Chapters” feature on
nook. While ADE displays a multilevel TOC, nook will display only one level. Consequently, an NCX set to
display in multiple levels in ADE
PART ONE
Section One
Chapter 1
Chapter 2
Section Two
Chapter 1
Chapter 2
Will display as a single levels on the nook
PART ONE
Section One
Chapter 1
Chapter 2
Section Two
Chapter 1
Chapter 2
VI.
Image optimization
The maximum viewing size of the nook screen is 600 x 730 pixels.
Copyright ©2010, Barnes & Noble
Images should be optimized for web delivery and can either be PNG, JPG or GIF. The choice of format is
optional and should be based on a compromise of image quality and file size. Typically, GIF supports a
maximum of 256 colors while JPG supports 16.7 million. PNGs support 24 bit color.
Cover images supplied for marketing purposes typically range between 500x600 to 600x730 pixels.
VII.
Files
Content should be organized into separate HTML or XHTML files. For example, Title_page.xhtml,
Contents.xhtml, Copyright.xhtml, Dedicatio.xhtml, Chapter_One.xhtml, Chapter_Two.xhtml, etc.
Each file should be less than 300kb and listed in the <manifest> of the OPF file. Files contained in the
ePub but not listed in the <manifest> and files listed in the <manifest> but not contained in the ePub will
interfere with nook performance.
VIII.
CSS/Fonts
When defining styles in the CSS, margins should be set as “pixels”, not “ems”, or “% of ems”. This will
optimize the viewing area regardless of selected font or type size.
The page margins should be set at 30 pixels on the top and sides, with 20 pixels on the bottom.
Embedded fonts are allowed: we discourage their inclusion due to licensing issues and the added
filesize.
Note that if you use Adobe InDesign to export an ePub and choose to encrypt embedded fonts, the
resulting ePub will produce numerous errors in epubcheck.
IX.
Special Characters
Nook supports Basic Latin UTF characters – see Appendix A for examples.
X.
•
•
•
•
•
•
•
•
•
General eBook Conventions
Covers are not mandatory in the eBook, but a Title Page is.
The page order does not need to follow the print book.
Blank pages are to be avoided.
It is helpful to have a Contents Page in the eBook, even if there is not one present in the print
version. The ebook Contents Page is linked to the individual chapters and helps with ebook
navigation.
Ideally, footnotes are linked.
A linked Index is not necessary, but there is usually a disclaimer indicating that the page references
are from the print version.
The Copyright page should show the ebook ISBN
Html tabular layout should only be used for tables, and not page formatting.
The text in tables rendered as images cannot be searched.
Copyright ©2010, Barnes & Noble
XI.
Appendix A
Basic Latin Unicode Characters
Unicode
code point
U+0000
U+0001
U+0002
U+0003
U+0004
U+0005
U+0006
U+0007
U+0008
U+0009
U+000A
U+000B
U+000C
U+000D
U+000E
U+000F
U+0010
U+0011
U+0012
U+0013
U+0014
U+0015
U+0016
U+0017
U+0018
U+0019
U+001A
U+001B
U+001C
U+001D
U+001E
U+001F
U+0020
U+0021
U+0022
U+0023
character
!
"
#
UTF-8
(hex.)
00
01
02
03
04
05
06
07
08
09
0a
0b
0c
0d
0e
0f
10
11
12
13
14
15
16
17
18
19
1a
1b
1c
1d
1e
1f
20
21
22
23
name
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
SPACE
EXCLAMATION MARK
QUOTATION MARK
NUMBER SIGN
Copyright ©2010, Barnes & Noble
U+0024
U+0025
U+0026
U+0027
U+0028
U+0029
U+002A
U+002B
U+002C
U+002D
U+002E
U+002F
U+0030
U+0031
U+0032
U+0033
U+0034
U+0035
U+0036
U+0037
U+0038
U+0039
U+003A
U+003B
U+003C
U+003D
U+003E
U+003F
U+0040
U+0041
U+0042
U+0043
U+0044
U+0045
U+0046
U+0047
U+0048
U+0049
U+004A
U+004B
U+004C
$
%
&
'
(
)
*
+
,
.
/
0
1
2
3
4
5
6
7
8
9
:
;
<
=
>
?
@
A
B
C
D
E
F
G
H
I
J
K
L
24
25
26
27
28
29
2a
2b
2c
2d
2e
2f
30
31
32
33
34
35
36
37
38
39
3a
3b
3c
3d
3e
3f
40
41
42
43
44
45
46
47
48
49
4a
4b
4c
DOLLAR SIGN
PERCENT SIGN
AMPERSAND
APOSTROPHE
LEFT PARENTHESIS
RIGHT PARENTHESIS
ASTERISK
PLUS SIGN
COMMA
HYPHEN-MINUS
FULL STOP
SOLIDUS
DIGIT ZERO
DIGIT ONE
DIGIT TWO
DIGIT THREE
DIGIT FOUR
DIGIT FIVE
DIGIT SIX
DIGIT SEVEN
DIGIT EIGHT
DIGIT NINE
COLON
SEMICOLON
LESS-THAN SIGN
EQUALS SIGN
GREATER-THAN SIGN
QUESTION MARK
COMMERCIAL AT
LATIN CAPITAL LETTER A
LATIN CAPITAL LETTER B
LATIN CAPITAL LETTER C
LATIN CAPITAL LETTER D
LATIN CAPITAL LETTER E
LATIN CAPITAL LETTER F
LATIN CAPITAL LETTER G
LATIN CAPITAL LETTER H
LATIN CAPITAL LETTER I
LATIN CAPITAL LETTER J
LATIN CAPITAL LETTER K
LATIN CAPITAL LETTER L
Copyright ©2010, Barnes & Noble
U+004D
U+004E
U+004F
U+0050
U+0051
U+0052
U+0053
U+0054
U+0055
U+0056
U+0057
U+0058
U+0059
U+005A
U+005B
U+005C
U+005D
U+005E
U+005F
U+0060
U+0061
U+0062
U+0063
U+0064
U+0065
U+0066
U+0067
U+0068
U+0069
U+006A
U+006B
U+006C
U+006D
U+006E
U+006F
U+0070
U+0071
U+0072
U+0073
U+0074
U+0075
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
[
\
]
^
_
`
a
b
c
d
e
f
g
h
i
j
k
l
m
n
o
p
q
r
s
t
u
4d
4e
4f
50
51
52
53
54
55
56
57
58
59
5a
5b
5c
5d
5e
5f
60
61
62
63
64
65
66
67
68
69
6a
6b
6c
6d
6e
6f
70
71
72
73
74
75
LATIN CAPITAL LETTER M
LATIN CAPITAL LETTER N
LATIN CAPITAL LETTER O
LATIN CAPITAL LETTER P
LATIN CAPITAL LETTER Q
LATIN CAPITAL LETTER R
LATIN CAPITAL LETTER S
LATIN CAPITAL LETTER T
LATIN CAPITAL LETTER U
LATIN CAPITAL LETTER V
LATIN CAPITAL LETTER W
LATIN CAPITAL LETTER X
LATIN CAPITAL LETTER Y
LATIN CAPITAL LETTER Z
LEFT SQUARE BRACKET
REVERSE SOLIDUS
RIGHT SQUARE BRACKET
CIRCUMFLEX ACCENT
LOW LINE
GRAVE ACCENT
LATIN SMALL LETTER A
LATIN SMALL LETTER B
LATIN SMALL LETTER C
LATIN SMALL LETTER D
LATIN SMALL LETTER E
LATIN SMALL LETTER F
LATIN SMALL LETTER G
LATIN SMALL LETTER H
LATIN SMALL LETTER I
LATIN SMALL LETTER J
LATIN SMALL LETTER K
LATIN SMALL LETTER L
LATIN SMALL LETTER M
LATIN SMALL LETTER N
LATIN SMALL LETTER O
LATIN SMALL LETTER P
LATIN SMALL LETTER Q
LATIN SMALL LETTER R
LATIN SMALL LETTER S
LATIN SMALL LETTER T
LATIN SMALL LETTER U
Copyright ©2010, Barnes & Noble
U+0076
U+0077
U+0078
U+0079
U+007A
U+007B
U+007C
U+007D
U+007E
U+007F
U+0080
U+0081
U+0082
U+0083
U+0084
U+0085
U+0086
U+0087
U+0088
U+0089
U+008A
U+008B
U+008C
U+008D
U+008E
U+008F
U+0090
U+0091
U+0092
U+0093
U+0094
U+0095
U+0096
U+0097
U+0098
U+0099
U+009A
U+009B
U+009C
U+009D
U+009E
v
w
x
y
z
{
|
}
~
76
77
78
79
7a
7b
7c
7d
7e
7f
c2 80
c2 81
c2 82
c2 83
c2 84
c2 85
c2 86
c2 87
c2 88
c2 89
c2 8a
c2 8b
c2 8c
c2 8d
c2 8e
c2 8f
c2 90
c2 91
c2 92
c2 93
c2 94
c2 95
c2 96
c2 97
c2 98
c2 99
c2 9a
c2 9b
c2 9c
c2 9d
c2 9e
LATIN SMALL LETTER V
LATIN SMALL LETTER W
LATIN SMALL LETTER X
LATIN SMALL LETTER Y
LATIN SMALL LETTER Z
LEFT CURLY BRACKET
VERTICAL LINE
RIGHT CURLY BRACKET
TILDE
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
<control>
Copyright ©2010, Barnes & Noble
U+009F
U+00A0
U+00A1
U+00A2
U+00A3
U+00A4
U+00A5
U+00A6
U+00A7
U+00A8
U+00A9
U+00AA
U+00AB
U+00AC
U+00AD
U+00AE
U+00AF
U+00B0
U+00B1
U+00B2
U+00B3
U+00B4
U+00B5
U+00B6
U+00B7
U+00B8
U+00B9
U+00BA
U+00BB
U+00BC
U+00BD
U+00BE
U+00BF
U+00C0
U+00C1
U+00C2
U+00C3
U+00C4
U+00C5
U+00C6
U+00C7
¡
¢
£
¤
¥
¦
§
¨
©
ª
«
¬
®
¯
°
±
²
³
´
µ
¶
·
¸
¹
º
»
¼
½
¾
¿
À
Á
Â
Ã
Ä
Å
Æ
Ç
c2 9f
c2 a0
c2 a1
c2 a2
c2 a3
c2 a4
c2 a5
c2 a6
c2 a7
c2 a8
c2 a9
c2 aa
c2 ab
c2 ac
c2 ad
c2 ae
c2 af
c2 b0
c2 b1
c2 b2
c2 b3
c2 b4
c2 b5
c2 b6
c2 b7
c2 b8
c2 b9
c2 ba
c2 bb
c2 bc
c2 bd
c2 be
c2 bf
c3 80
c3 81
c3 82
c3 83
c3 84
c3 85
c3 86
c3 87
<control>
NO-BREAK SPACE
INVERTED EXCLAMATION MARK
CENT SIGN
POUND SIGN
CURRENCY SIGN
YEN SIGN
BROKEN BAR
SECTION SIGN
DIAERESIS
COPYRIGHT SIGN
FEMININE ORDINAL INDICATOR
LEFT-POINTING DOUBLE ANGLE QUOTATION MARK
NOT SIGN
SOFT HYPHEN
REGISTERED SIGN
MACRON
DEGREE SIGN
PLUS-MINUS SIGN
SUPERSCRIPT TWO
SUPERSCRIPT THREE
ACUTE ACCENT
MICRO SIGN
PILCROW SIGN
MIDDLE DOT
CEDILLA
SUPERSCRIPT ONE
MASCULINE ORDINAL INDICATOR
RIGHT-POINTING DOUBLE ANGLE QUOTATION MARK
VULGAR FRACTION ONE QUARTER
VULGAR FRACTION ONE HALF
VULGAR FRACTION THREE QUARTERS
INVERTED QUESTION MARK
LATIN CAPITAL LETTER A WITH GRAVE
LATIN CAPITAL LETTER A WITH ACUTE
LATIN CAPITAL LETTER A WITH CIRCUMFLEX
LATIN CAPITAL LETTER A WITH TILDE
LATIN CAPITAL LETTER A WITH DIAERESIS
LATIN CAPITAL LETTER A WITH RING ABOVE
LATIN CAPITAL LETTER AE
LATIN CAPITAL LETTER C WITH CEDILLA
Copyright ©2010, Barnes & Noble
U+00C8
U+00C9
U+00CA
U+00CB
U+00CC
U+00CD
U+00CE
U+00CF
U+00D0
U+00D1
U+00D2
U+00D3
U+00D4
U+00D5
U+00D6
U+00D7
U+00D8
U+00D9
U+00DA
U+00DB
U+00DC
U+00DD
U+00DE
U+00DF
U+00E0
U+00E1
U+00E2
U+00E3
U+00E4
U+00E5
U+00E6
U+00E7
U+00E8
U+00E9
U+00EA
U+00EB
U+00EC
U+00ED
U+00EE
U+00EF
U+00F0
È
É
Ê
Ë
Ì
Í
Î
Ï
Ð
Ñ
Ò
Ó
Ô
Õ
Ö
×
Ø
Ù
Ú
Û
Ü
Ý
Þ
ß
à
á
â
ã
ä
å
æ
ç
è
é
ê
ë
ì
í
î
ï
ð
c3 88
c3 89
c3 8a
c3 8b
c3 8c
c3 8d
c3 8e
c3 8f
c3 90
c3 91
c3 92
c3 93
c3 94
c3 95
c3 96
c3 97
c3 98
c3 99
c3 9a
c3 9b
c3 9c
c3 9d
c3 9e
c3 9f
c3 a0
c3 a1
c3 a2
c3 a3
c3 a4
c3 a5
c3 a6
c3 a7
c3 a8
c3 a9
c3 aa
c3 ab
c3 ac
c3 ad
c3 ae
c3 af
c3 b0
LATIN CAPITAL LETTER E WITH GRAVE
LATIN CAPITAL LETTER E WITH ACUTE
LATIN CAPITAL LETTER E WITH CIRCUMFLEX
LATIN CAPITAL LETTER E WITH DIAERESIS
LATIN CAPITAL LETTER I WITH GRAVE
LATIN CAPITAL LETTER I WITH ACUTE
LATIN CAPITAL LETTER I WITH CIRCUMFLEX
LATIN CAPITAL LETTER I WITH DIAERESIS
LATIN CAPITAL LETTER ETH
LATIN CAPITAL LETTER N WITH TILDE
LATIN CAPITAL LETTER O WITH GRAVE
LATIN CAPITAL LETTER O WITH ACUTE
LATIN CAPITAL LETTER O WITH CIRCUMFLEX
LATIN CAPITAL LETTER O WITH TILDE
LATIN CAPITAL LETTER O WITH DIAERESIS
MULTIPLICATION SIGN
LATIN CAPITAL LETTER O WITH STROKE
LATIN CAPITAL LETTER U WITH GRAVE
LATIN CAPITAL LETTER U WITH ACUTE
LATIN CAPITAL LETTER U WITH CIRCUMFLEX
LATIN CAPITAL LETTER U WITH DIAERESIS
LATIN CAPITAL LETTER Y WITH ACUTE
LATIN CAPITAL LETTER THORN
LATIN SMALL LETTER SHARP S
LATIN SMALL LETTER A WITH GRAVE
LATIN SMALL LETTER A WITH ACUTE
LATIN SMALL LETTER A WITH CIRCUMFLEX
LATIN SMALL LETTER A WITH TILDE
LATIN SMALL LETTER A WITH DIAERESIS
LATIN SMALL LETTER A WITH RING ABOVE
LATIN SMALL LETTER AE
LATIN SMALL LETTER C WITH CEDILLA
LATIN SMALL LETTER E WITH GRAVE
LATIN SMALL LETTER E WITH ACUTE
LATIN SMALL LETTER E WITH CIRCUMFLEX
LATIN SMALL LETTER E WITH DIAERESIS
LATIN SMALL LETTER I WITH GRAVE
LATIN SMALL LETTER I WITH ACUTE
LATIN SMALL LETTER I WITH CIRCUMFLEX
LATIN SMALL LETTER I WITH DIAERESIS
LATIN SMALL LETTER ETH
Copyright ©2010, Barnes & Noble
U+00F1
U+00F2
U+00F3
U+00F4
U+00F5
U+00F6
U+00F7
U+00F8
U+00F9
U+00FA
U+00FB
U+00FC
U+00FD
U+00FE
U+00FF
ñ
ò
ó
ô
õ
ö
÷
ø
ù
ú
û
ü
ý
þ
ÿ
c3 b1
c3 b2
c3 b3
c3 b4
c3 b5
c3 b6
c3 b7
c3 b8
c3 b9
c3 ba
c3 bb
c3 bc
c3 bd
c3 be
c3 bf
LATIN SMALL LETTER N WITH TILDE
LATIN SMALL LETTER O WITH GRAVE
LATIN SMALL LETTER O WITH ACUTE
LATIN SMALL LETTER O WITH CIRCUMFLEX
LATIN SMALL LETTER O WITH TILDE
LATIN SMALL LETTER O WITH DIAERESIS
DIVISION SIGN
LATIN SMALL LETTER O WITH STROKE
LATIN SMALL LETTER U WITH GRAVE
LATIN SMALL LETTER U WITH ACUTE
LATIN SMALL LETTER U WITH CIRCUMFLEX
LATIN SMALL LETTER U WITH DIAERESIS
LATIN SMALL LETTER Y WITH ACUTE
LATIN SMALL LETTER THORN
LATIN SMALL LETTER Y WITH DIAERESIS
Copyright ©2010, Barnes & Noble