For terminals with single-line representation, it is normal to assign either a terminal designation or just a terminal strip designation.
EPLAN makes both methods of designation available when you insert a single-line terminal symbol.
You cannot store connection or part data at terminals with single-line representation. In accordance with this, the Connections and Parts tabs in the Properties <...> dialog are not displayed.
In contrast to this, you can place terminal strip definitions on single-line schematic pages, to which you can then assign parts.
See also