Uncovered dairy in a clean fleishig [=meat] oven — If one cooks fleishig in an oven and ensures it remains clean (i.e. the oven has no meat residue), one may bake an uncovered dry dairy product in the oven. This may be done as long as there is no uncovered meat product in the oven at the same time as the dry dairy product. "Dry" means the finished product has little or no liquid.
From what little I know of the rules of milk and meat, the reason for requiring that the dairy food be dry is that otherwise it raises steam when baking: the steam, and the food abutting it, thus re-absorbs the meat taste that got absorbed into the walls of the oven the last time liquidy meat was baked. But that would seem to be a concern any time the dairy food is liquidy while baking (once the oven is hot), whether it is liquidy when put into the oven, when removed, or any time in between. Why does the Star-K specify that the finished product must be dry?