BACKGROUND...Ah, HERE WE GO, in a FAQ for skaters:
[8] What is the "Katarina Rule"?
This refers to the guidelines for skaters' costumes that were adopted after Katarina Witt showed up at the 1988 European championships wearing a skimpy showgirl costume trimmed with feathers. (Many people were dismayed by the increasing emphasis on theatrical costuming and displays of pulchritude, rather than athleticism.)
Ladies are now required to wear skirts and pants "covering the hips and posterior".
Men cannot wear clothing that is sleeveless or that exposes the chest. A more recent rule change requires men to wear trousers and not tights.
Clothing is also supposed to be free from "excessive decoration", such as feathers that can come loose and create a safety hazard on the ice.
So it's an equipment reg.
~Susan