The signature PAdES compliance level.
The PadesLevel enumeration may take the following values:
When you call one of the Sign methods, this property specifies
the desired compliance level the document should conform to.
When you call Validate,
this value will be set to the highest compliance level the
signature conforms to. If Validate has not been called on an
existing signature, this value will remain set to its default value
Any PAdES compliance level greater than PAdES_B_B, means that it
is also compliant to any of the preceeding PAdES compliance levels
in the order specified above. So PAdES_B_LT is also PAdES_B_T and
If a compliance level of PAdES_B_T or above is specified when
signing, a Timestamp Authority will be required. If a TimestampServiceUrl is specified then
that value is used. If no TimestampServiceUrl is specified and
the signing certificate has a certificate extension with Oid
1.2.840.1135188.8.131.52.1, this extension value is used. Otherwise an
exception is thrown.
If a compliance level of PAdES_B_LT or PAdES_B_LTA is specified
when signing, the signing certificate should have online OCSP
and/or online CRL certificate extensions specified in one of the
certificates in the chain of trust.
PAdES baseline compliance levels are specified in ETSI TS 103
172 which can be found at www.etsi.org.