In this MSDN article, MS explains how to specify other delimiters besides commas for csv-type exports from SSRS 2005:
http://msdn.microsoft.com/en-us/library/ms155365%28SQL.90%29.aspx
...however, literal tab characters are stripped by the config file parser, and it doesn't appear that MS has provided a workaround. This entry on Microsoft Connect seems to confirm this:
http://connect.microsoft.com/SQLServer/feedback/ViewFeedback.aspx?FeedbackID=357527
...has anyone developed a way to export tab-delimited files from SSRS 2005? Or perhaps developed an open-source custom renderer to get the job done?
Note: I've heard of manually appending &rc:FieldDelimiter=%09 via URL access, but that's not an acceptable workaround for my users and doesn't appear to work anyways.