In order to start the Formatted Data Editor with a template applied against a data set, the desired template must first be defined within the data set's properties panel. The template association properties panel is available on sequential data sets and VSAM clusters by default, and only on PDS members that have had the .tdat extension appended to them.
In the template association panel, there are two options for setting the template to be associated with a data set. The first option allows you to enter the remote data set location manually if you know the fully qualified path of the template. The second option enables a template to be selected from a navigation tree of current data sets known to RSE. The drop-down box contains the RSE MVS™ filters currently available in the Remote Systems view. To search for a template, select the appropriate filter from the drop-down box and a navigation tree of the data set hierarchy will open in the window. Browse to the desired template and select it. Optionally, the “Known Templates and Copybooks only” check box can be selected so that the results shown in the hierarchy are only data sets with the .tmpl, .cpy, and .inc extensions.

Alternatively, templates can also be applied in the Formatted Data Editor if a data set is initially opened without a template applied. If a data set is opened in the Formatted Data Editor with no template applied, as long as the data set has not been modified, a template may be applied. However, once changes have been made to the data set, the option to apply a template from within the editor is disabled.
To apply a template to a data set already opened in the Formatted Data Editor:

After the template is applied, the Formatted Data Editor will refresh to display the data set with the formatting defined in the template.