Circumcision Bridge "Piercing"
When a circumcision is done, both the glans and what's left of the foreskin tissue have raw edges. Normally these fuse on the shaft, behind the head, but it is not uncommon for some of the skin on the foreskin to actually form a bridge (similar to a bipedicle flap in some ways) of skin from the coronal ridge to the shaft with enough space underneath it to wear jewelry — in effect a frenum piercing without ever having to have it pierced as an adult. Should the person desire it, this piercing can be stretched as well.
If you have a skin bridge of this type, simple cosmetic surgery can also (mostly) remove it depending on the severity.