Intended as a canonical answer to the many questions we have about damage to carbon parts.

It is well known that carbon fiber parts can be damaged and fail, and carbon parts can be fragile when stressed in certain ways, but we get a large number of questions on this site asking if a carbon part (Frame, rim, stem) with damage is a concern or not. Many of these parts are obviously suffering no more than a minor cosmetic blemish, and very few are suffering from clearly significant damage. Most fall into the gap between where physical inspection is required to make an assessment.