Hi I believe it was intentional to filter HTML from the credits field. Anything is possible with extra Javascript but I am afraid there is no simple workaround for now. If you are interested in the JS workaround, send me a link to your post/page and I can help you. (You can email me directly at hyunsupul@gmail.com) I can make a change in the next release of Aesop to allow hyperlinks if you would like.
Thank you so much! I appreciate it. AESOP is an essential tool for us, a release with that functionality would be amazing, since image copyright attribution would be greatly simplified in compliance with certain institutions requirements if one could use html hyperlinks in the captions.