Suggestions

In some cases, Little Snitch automatically creates a rule for you, e.g. if you have selected Alert Mode but it was impossible to show an alert. These rules are often temporary rules. They are usually already expired when you open Little Snitch Configuration, but they contain valuable information about connections which were automatically allowed or denied and you might want to turn them into permanent rules. Little Snitch therefore preserves these expired rules as rule templates for you. They are available in the Suggestions section of Little Snitch Configuration.

Rules which require your attention, because they are invalid or redundant are also listed under Suggestions.

Suggestions Section

Rule suggestions

Login — Temporary rules for connections which occurred before you logged in to your computer. Little Snitch denied these connections, short of a possibility to ask.
Full Screen — Temporary deny rules which were created automatically while an application captured the entire screen (like games often do) and Little Snitch could not show a connection alert. You probably won’t see the suggestion before the rule has expired.
Timeout — Temporary rules that were automatically created after an alert timeout. Alert timeouts are off by default and can be enabled in Preferences > Alert > Confirm connection alert automatically.
Expired — Expired temporary rules created by you. Instead of deleting these rules, Little Snitch lists them as suggestions because you may want to turn some of them into permanent rules.

Maintenance

Invalid — The corresponding application or process no longer exists.
Redundant — Redundant Rules. You may want to delete them.
Unnecessary Priority — Rules with unnecessary priority. You may want to lower the priority.
No Identity Check — Rules which do not check the process identity or match untrusted processes. Consider enabling the check for these rules.
Identity Mismatch — Rules that were created to prevent further network communication in case of a failed process identity check.