The 
                  spine element represents the section of the cover that overlays the bound inner side of a publication.
                  
               
               The spine typically contains the author/editor name(s), title and the publisher/imprint logo. Information on the spine is
                  often truncated because of space constraints.
               
             
            Usage Example
<cover>
    <spine>
        <block>
            <ln>On the Origin of Species</ln>
            <ln><name>Darwin</name>.</ln>
        </block>
        <block role="imprint">
            <ln>
                <name role="place">London</name>
            </ln>
            <ln>
                <name>John Murray</name>
            </ln>
        </block>
    </spine>
    …
</cover>
    Allowed parents
            cover
               
            
            Allowed children
            This element may contain text.
            
            This element may contain the following children: abbr, 
               address, 
               annoref, 
               annotation, 
               block, 
               ssml:break, 
               char, 
               citation, 
               code, 
               d, 
               definition, 
               emph (text variant), 
               emph (phrase variant), 
               expansion, 
               hd, 
               xforms:input, 
               rend:linebreak, 
               ln, 
               m:math, 
               name, 
               note, 
               noteref, 
               num, 
               object (block variant), 
               object (text variant), 
               object (phrase variant), 
               p, 
               ssml:phoneme (text variant), 
               ssml:phoneme (phrase variant), 
               ssml:prosody (text variant), 
               ssml:prosody (phrase variant), 
               quote, 
               xforms:range, 
               ref, 
               its:ruby, 
               s, 
               ssml:say-as (text variant), 
               ssml:say-as (phrase variant), 
               xforms:secret, 
               sel:select, 
               xforms:select, 
               xforms:select1, 
               span (text variant), 
               span (phrase variant), 
               sub, 
               ssml:sub (text variant), 
               ssml:sub (phrase variant), 
               sup, 
               term, 
               xforms:textarea, 
               time, 
               ssml:token (text variant), 
               ssml:token (phrase variant), 
               transition and 
               w
               
            
            Content model and additional requirements
            
               optional attributes: 
@about, 
                  
@by, 
                  
@class, 
                  
@content, 
                  
@datatype, 
                  
@desc, 
                  
@its:dir, 
                  
@its:translate, 
                  
@property, 
                  
@rel, 
                  
@resource, 
                  
@rev, 
                  
@role, 
                  
@sel:selid, 
                  
@typeof, 
                  
@xml:base, 
                  
@xml:id, 
                  
@xml:lang and 
                  
@xml:space 
               a choice of
                  
                  
                  
                  or 
one or more of 
                     
                     a choice of either one of the 52 elements: 
abbr, 
address, 
annoref, 
annotation, 
char, 
citation, 
code, 
d, 
definition, 
emph, 
emph, 
expansion, 
its:ruby, 
ln, 
m:math, 
name, 
note, 
noteref, 
num, 
object, 
object, 
quote, 
ref, 
rend:linebreak, 
s, 
sel:select, 
span, 
span, 
ssml:break, 
ssml:break, 
ssml:phoneme, 
ssml:phoneme, 
ssml:prosody, 
ssml:prosody, 
ssml:say-as, 
ssml:say-as, 
ssml:sub, 
ssml:sub, 
ssml:token, 
ssml:token, 
sub, 
sup, 
term, 
time, 
w, 
w, 
xforms:input, 
xforms:range, 
xforms:secret, 
xforms:select, 
xforms:select1 or 
xforms:textarea 
                        or text
end of choice 
                     
                   
                  end of choice 
               Note that in addition to restrictions presented in the content model  above, 
                  					use of this element must also respect the following requirement:
                  
                     - The 
                        
spine element must neither be empty nor contain only whitespace.
                        
                      
                  
                  Such requirements take precedence over any conflicting statements in the
                     						content model or in the lists above of allowed children and parents.
                  
                
             
            Namespace
            http://www.daisy.org/ns/z3998/authoring/