This read-only value is the current-interval count of C-bit Severely Errored Seconds, seconds with a high enough density of C-bit coding violations to be classified as severe, applicable only for DS3. It represents the most serious tier of C-bit-framing degradation, analogous to PSESs for the P-bit statistics, and generally warrants faster escalation than ordinary CESs. For example, a rise in csDs3StatCurrentCSESs alongside csDs3StatCurrentUASs would strongly suggest the C-bit framing circuit is experiencing significant, service-affecting quality problems rather than isolated minor errors.