Ceramic bowls come in a variety of sizes and designs. Some are glass-based, others have glaze coating and still others are unglazed and claylike. Because of these differences, which may not be visibly noticed, manufacturers often include safe usage indications to let you know if the bowl is safe for some or all appliances. Some glazes can cause overheating, cracking or changes to the chemical structure of the glaze when exposed to oven heat.
Pick up the bowl in one hand.
Carefully turn the bowl upside down and inspect the markings on the bottom. Look for information on safe uses. For example the bowl may be labelled as dishwasher- and microwave-safe.
Look specifically for an icon or words that indicates the bowl is "oven safe." An icon of an oven may also be present.
Check the packaging or booklet that came with the bowl for information about oven-safe uses. In the absence of information, assume the bowl is not safe for oven use.
Note that a "microwave safe" indication often includes a series of wavy lines; this is not the same as "oven safe."