Test scenarios for security bindings / editing required?

Should we test the ones that are described in section 4 of part 2[1]?

Payload security, payload authentication, and TLS bindings.

I must confess that this section is the most vague one on the spec. I
still don't understand what is mean by the "Variant" column in the
tables of section 4.1 and 4.2. 

There's no description of what is meant by "variant" or why the column
doesn't give variants to all the options in the table.

I'm not sure if we require test scenarios here. However, it sure looks
like it requires some editing.

[1] http://www.w3.org/TR/xkms2-bindings/#XKMS_2_0_Section_4