1. If the Contents window is not visible, enable it by clicking View | Show/hide | Contents (verify there is a check mark next to it).
2. Select the first map layer or object in the Contents window tree and uncheck the check box next to the layer to turn off the visibility to identify the layer in the plot window.
3. Recheck the check box to turn the layer visibility back on.
4. Right click over the layer and click Rename Object.
   
5. Enter a descriptive name for the layer and click OK.
6. Repeat for all other map layers or objects you wish to name.

Updated December 2021