A system 0C1 abend might occur when IEBCOPY detects a catastrophic situation. If an event happens that "absolutely should not occur," a short string of text might be present in the load module at the abend PSW location.
These abends are controlled by conditional assembly and are not normally included in the shipped product. However, abends might be present in ESP/ISP/EIO/pre-release code or test APARs (AYnnnnn).