Hi Kong,
In order to take a transfer out of the public logs you have some options:
1. Change the access of the transfer to something other than Public.
-Note that if the transfer has expired then you cannot change the access in 4th edition. If you repost the transfer, you can then change the access level.
2. Delete the public transfer from the Info Exchange Activity Center.
3. Remove the Project containing the public transfers from Info Exchange.
4. In 5th Edition, we added a task to the Administration page specifically to make this process easier. On the transfers tab there is now a Modify Access Level task that will allow you to select any or all Public Transfers (even if they have expired) and change their access level for a single project or across all projects.
Hope that helps,
Chad