Adding Icons to served files

If you wish to add a new icon into your button or button bar setup using the '+', you may have noticed that it does not stick in a served file.  When you close out and go back in, the new icon has again disappeared.  One must unserve the file and add it locally.  However, I just discovered that if you add the icon into a local button or button bar then copy the button bar and paste it into the served file, it appears for selection in other buttons in the served file and remains even if you then delete the pasted button bar back out.

This has been useful, not only in adding new icons, but keeping a button bar with all icons is a quick way to add your favorites into any other file.  Originally, I was keeping my svg files and inserting one at a time when I created a new file, LOL.