Sony PRS-350 - Manual (Page 73)

Collections
7
Table of Contents Index
Removing contents
Even if you delete content in a collection, the
corresponding content will remain undeleted on the
Reader.
1
Tap [Collections] at [Home] menu  tap a
collection.
2
Press OPTIONS  tap [Remove Content].
3
Tap the thumbnail of each content to be
deleted  [Done]  [Yes].
Tips
 To select all contents, press OPTIONS after step 2 above 
tap [Select All].
 When you delete contents in [Books] or [Periodicals],
corresponding contents are also deleted from relevant
collections.