[BaseCamp] customizing waypoints

[saddle sore]

While in BaseCamp, open a waypoint properties box, click on the down arrow
at Display and see all the possible waypoint icons to use.  Scroll down to
the bottom and I find "Custom" with just a line of blue dots.  How do I
create a customized waypoint in BaseCamp and then save it so I can use it
for other waypoints and routes?

I have some specific symbols and some specific letters in mind that I'd
like for waypoint icons (yes I realize my GPS will not read them, but I
used certain waypoints for routing and then change them before transferring
to the GPS).

Thoughts??

Thanks, Joe Y.