This read-only counter tracks the number of errors detected on this device, and per the printer's own additional documentation, the CLJ8500 specifically counts this as critical alerts that have been entered into the printer's error log rather than every minor logged event. Because it is a Counter type with no defined starting value, an admin should watch it for increases rather than compare it against zero. For example, an admin who sees hrdeviceerrors climb by three overnight would know three new critical alerts were logged, and could then check the numbered error-code and error-time-stamp objects to see exactly what those alerts were.