We use this when we remove a replica of a database so that client can continue to access the file on the another server. The format looks like this:
[NotesRedirectFile]
Type=Move
RepID=87654321:12345678
Title=lesleysRedirTest
Ref=CN=APP001/OU=SRV/O=MyCompany!!isg\lesleysRedirTest.nsf
The name of this file is lesleysRedirTest.nrf (matching the name of the db, lesleysRedirTest.nsf) and, it goes in the directory of the server that the db replica is being deleted from.
In this case we deleted the db from server APP002/SRV/MyCompany and clients clicking the bookmarks or workspace icons going to APP002 will automatically have their links to APP002 deleted and replaced with links to the db on APP001.
If you need to get a hold of a replica id of the db, in case you forgot to create the redir on delete, you can get one from the remaining dbs and get a db link. When you paste the db link in to a text editor you will get the following, with the replica id in it...
lesleysRedirTest
<NDL>
<REPLICA 87654321:12345678>
<HINT<CN=APP001/OU=SRV/O=MyCompany</HINT>
<REM>lesleysRedirTest</REM>
</NDL>