A Shiner is a piece of exposed bone showing through the meat on the top side of raw ribs.

Pork Rib Shiner

Shiners are the result of ribs being trimmed too close and exposing the bone.  This is an indicator that there may be only a little meat left on the bones to cook.  BBQ cooks try to avoid shiners if possible.

Shiner is also a beer drunk in Texas by BBQ aficionados while waiting for their brisket or ribs to cook.

BBQ Nuts Enjoy a Shiner

For the record we enjoy Shiner here in the Mid-Atlantic too!