I believe there was a product support issue raised on this recently - I'm not sure if it was yours.
In any case I believe the answer you should receive in that situation, other than making sure you discuss it with your account manager, is that the physical location where Clarity is installed doesn't really matter. Internet, intranet, DMZ, cloud, externally hosted, etc., none of that really matters directly from a CA Support perspective.
What does matter are the items we call out in the guides, and your obligations from a contractual perspective (e.g. how many environments you can install, with one of them only being production, etc.).
As far as the guides are concerned, you should be sure that your platforms conform to the Release Notes - Compatibilities sections for our servers, which include a link to this article: CA Support Statement for Virtualization and also these notes:
Notes:
5)Databases can be run on any vendor-supported platform. Oracle SPARC T4 and earlier T-Series servers are not supported. Production databases are not supported on software virtualized operating systems; examples include VMware vSphere, Microsoft Hyper-V, and Citrix XenServer. AIX LPARS, HP-UX VPARS, and Solaris containers do not fall into this category and remain supported. It is also recommended that any downstream environments that are intended for performance or high concurrency testing match what is used in production.
... (see the full section for more details) ...
You will need to check your providers on those points.