The severity code is the letter following the message number and indicates the level of attention called for by the condition. Messages with severity "I" are informational messages and do not usually require any corrective action. In general, if more than one runtime message appears, the first noninformational message indicates the problem. For a complete list of severity codes, severity values, condition information, and default actions, see z/OS Language Environment Programming Guide for 64-bit Virtual Addressing Mode.