Strict

Items are added to the security header in a principle of "declare before use".

Lax

Items are added to the security header in any order that conforms to WSS: SOAP Message Security.

LaxTsFirst

Same as Lax except that the first item in the security header must be a wsse:Timestamp. Note that the wsse:Timestamp property must also be set to true in this case.

LaxTsLast

Same as Lax except that the last item in the security header must be a wsse:Timestamp. Note that the wsse:Timestamp property must also be set to true in this case.