MFS files are stored in the host in visual format. The default bidirectional format for Rational Developer for System z is Smart Logical. The user must associate the correct bidirectional conversion tables in the file system mapping for .mfs files because the default setting does not assume bidirectional conversion.
Visual editing of bidirectional data is enabled after "Bidirectional options enabled" is selected in Preference. To do this, select .
Even after visual editing is enabled, bidirectional data is saved in .mfs files in Smart Logical format. This format is very similar to standard Windows® logical format, but is based on extensive use of bidirectional LRM markers. For additional information about Smart Logical support, see the information about the zIDE tool.
To edit bidirectional data in the Smart Logical format, use the System z® LPEX editor. The LPEX editor provides a special visual line for this purpose. To access the visual line in LPEX, use the pop-up menu to select , or use the Alt+= key combination. For more information about System z LPEX bidirectional support, see the LPEX documentation.
To edit bidirectional data in the MFS editor Source view, use the Ctrl+NumLock key combination on the selected line.
In order to activate bidirectional support, select and select "Bidirectional options enabled."

When you select the Enable bidirectional settings button option, the same set of bidirectional settings is made available in the MFS Editor toolbar.
When a bidirectional settings button is enabled, you can set dynamically the bidirectional options described in this topic.