Custom rules can be configured by clicking on the Custom Rules tab. The rules must be entered in a format compatible with Suricata. Additional Suricata documentation can be found at https://suricata.readthedocs.io/en/suricata-4.1.4/
To add a new rule click Add.
Name: The name associated to the rule.
Rule: The text area for each rule entry can have one or more rule definitions on their own line within the text area. This allows the grouping of multiple rule definitions within one named rule entry.