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doc/todo/hidden_files.mdwn

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+Add a `git annex hide $file` that behaves like drop, checking counter info
+and updating location log to say the current repo no longer has a file --
+but does not actually remove the content.
+
+Then `git annex unused` can be used to clean it up later. And in the
+meantime, it's still locally accessible. This can be useful if you're
+planning to need to free up space later, but want to hold onto the content
+for a while. Possibly you'll be disconnected later, so it's easier to push
+out that intent now.
+
+--
+
+TODO:
+
+* Make 100% sure this is safe. Drop, etc should never check content files
+  are present on other repos if the location log doesn't say the repo
+  has the content.
+
+* What will `git annex get` do if it's asked to get a file that has been
+  hidden?