Thank you for suing our service.
It is not possible at the moment, however you will have the ability to add custom characteristics with the Sitefinity version that will be released after Sitefinity 6.0.
Please inform us if you have further questions. I will be glad to answer you.
the Telerik team
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items