Section 6.4:
Several occurrences of "preference" rather than "preferences"  
attrribute:
"A user agent must initialize the preference attribute in accordance  
with this specification."
"Upon getting the preference attribute, the user agent must return a  
Storage object that represents the storage area for the origin of a  
widget."
"Whenever the user agent performs any of the following operations on  
the Storage object of a preference attribute, the user agent must  
obtain the storage mutex in manner specified in the [WebStorage]  
specification:"
"If a user agent has not previously associated a storage area with the  
origin of a widget, then the user agent must initialize the preference  
attribute."
"The steps to initialize the preference attribute are as follows:"
S