Can a crew Dragon dock with a CST-100?

[whitelancer64]

Can a crew Dragon dock with a CST-100?

Yes, I know that their docking mechanisms are different, but both are IDSS (International Docking System Standard) compliant. However, what I don't know is if IDSS compliant systems can dock with each other. Does anyone here know?

I'm wondering if something like an Apollo-Soyuz Test Project mission is possible, except a docking adapter would not be required, or would it?

Also this would be useful for an on-orbit rescue if one vehicle or the other was rendered inoperable.

[BrianNH]

The IDSS docking interface is fully androgynous about one axis, meaning the interface
configuration is capable of mating to an identical configuration. During docking, one
androgynous soft capture interface must be active (active mode), while the other
androgynous soft capture interface remains retracted and locked in place, or passive
(passive mode).

It sounds like they would be able to.  The full standard is here.

http://www.internationaldockingstandard.com/download/IDSSIDD-DCN-001_Revision_C.pdf

[whitelancer64]

It sounds like they would be able to.  The full standard is here.

http://www.internationaldockingstandard.com/download/IDSSIDD-DCN-001_Revision_C.pdf

To quote the standard: "This International Docking System Standard (IDSS) Interface Definition Document (IDD) is the result of a collaboration by the International Space Station membership to establish a standard docking interface to enable on-orbit crew rescue operations and joint collaborative endeavors utilizing different spacecraft."

So the IDSS was meant to at least enable the sort of interaction I'm asking about. That's probably the best answer I'm going to get, thank you!