Known Error
A problem that has been analyzed and has not yet been resolved. Not all known errors are fixed immediately; some may have a workaround, while others may be accepted as permanent limitations due to cost/risk.
Impact
Documenting known errors speeds up incident resolution. It stops the help desk from re-investigating the same bug 50 times.
Weinto take
A "Known Error" database is a To-Do List for Automation. If there is a workaround, script it. If it can't be fixed, architect around it. Don't let your Known Error database become a graveyard of accepted mediocrity.