No, they're numerical because it works with numbers.
Best you can do is agree with your users what number a shirt-size should be. Or use a custom field for it first, and use story points for more accurate numbers afterwards
Further to the reply from @Nic Brough [Adaptavist] there are lots of reports and other actions built around the story points and these would not function if you used a shirt-size approach. In particular you may consider the scope size for a sprint, the epic/release burndown report...
Just the FAQs! Welcome to the Community, and this Focused-FAQ! Here, we've pulled together some of the most frequently asked questions associated with Jira Service Desk (JSD). We hope ...
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG
You're one step closer to meeting fellow Atlassian users at your local meet up. Learn more about AUGs