...

... Is the registration fee for the Symposium refundable ...

I suggest that you register and pay - to make sure there is room for you.

Then, if you cannot show up, contact Martha ASAP, and advise her that your registration is available to someone else. She will find a suitable recipient for your graciousness.

YOU get a tax receipt ... and someone else gets the experience. EVERYONE wins.

Clint, K6LCS