If you have a sequence of space separated words on a single line, i.e. "link1 link2 link3 link4 ..." and those words match radio targets, every other word/link will not be recognized as a radio link. In this example link2 and link4 will not be links. describe-char correctly identifies the good links:
face org-link help-echo "Radio target link" but does not identify the alternate links as such, which are displayed in the default face and do not respond to click. Inserting another character between them, i.e. "link1 - link2 - link3 ..." works correctly. -- Jay Dresser
