| Field Name | Type | Description | 
|---|---|---|
| TTP0..n | TTPBaseType | Characterizes a single cyber threat adversary Tactic, Technique or Procedure. This field is implemented through the xsi:type extension mechanism. The default and strongly recommended type is TTPType in the http://stix.mitre.org/TTP-1 namespace. This type is defined in the ttp.xsd file or at the URL http://stix.mitre.org/XMLSchema/ttp/1.0/ttp.xsd. 
 | 
| Kill_Chains0..1 | KillChainsType | The Kill_Chains field characterizes specific Kill Chain definitions for reference within specific TTP entries, Indicators and elsewhere. |