An adult student asked me to look at her skates tonight because she was worried that they were breaking down. The Riedell boots were different-looking with decorative stitching and they had this bronze metal rectangle between the eyelets and the hooks, where the boot was bulging/creasing a little. When I put my finger inside to flex the crease, I realized that there was another eyelet under the doo-hickey that she wasn't using.
The doo-hickey is called a "Lace Lock" -- you thread the laces through the hole, toggle the little lock to pull the lace up and out, then release to lock the lace in place so it doesn't slip.
They're Riedell Gold Medallions (300) that were discontinued back in 2008, right around the time that she purchased them. She bought the skates mail order, so she didn't realize that the lace lock was a feature, she also thought it was decorative. If she uses it, it'll probably stabilize her foot a bit since that's where it's bulging - she's essentially been skipping a lace eyelet.
I love a research mystery - she didn't remember what model she bought. They came as a set with a Jubilee blade. She's gotten good use out of them to have them last three years. She is a low-level adult freestyle skater, but she practices regularly.