Continuing the discussion from White label access to my customers:
This means I can’t use any other sub domain because Sitejet might change or modify it’s system.
So, we should use a domain that is not associated with our brand or main site? How can we add * ? Sitejet can just change and then one of our existing subdomains won’t work anymore?
Hey there,
Of course, you can set up any and as many subdomains as you like. But curious how you came to this conclusion 
Setting up a Wildcard CNAME is not mandatory for you as a Sitejet user 
- however, this makes things much easier. Thanks to the Wildcard CNAME entry all links will be created with your domain e.g. for the Login, the customer portal login, or the preview links.
For example: Sitejet uses the “my.” and “partner.” subdomains for white labeling. Therefore, we recommend that you do not assign your own subpages to these, or other subdomains used by Sitejet, which include “api.”, “cms.”, “preview.”, and “preset.”.
In addition to that, a Wildcard CNAME is also makes things easier with the new infrastructure for US based servers. If you do not want to set a Wildcard CNAME or are not able to do so because your domain provider declines, then you can just set up a usual CNAME for your domain.
By the way, we usually do not change anything of your setup or website - unless you ask nicely 
Let me know if that helps?
Thanks for the reply. I understand it is an optional feature but I have a question based on what you said:
If you do not want to set a Wildcard CNAME or are not able to do so because your domain provider declines, then you can just set up a usual CNAME for your domain.
You mean manually set up CNAME for each of the subdomains you mentioned
my
partner
api
cms
preview
preset
the conversation that I referred to made it sound like these can and will change at any time without notice.
Yes, you can set them up manually, if you need to.
We do not change any of these very important settings without informing every one of you. That would be a very big change - you would not miss this kind of notification. 
But to give you some insight - there is no internal plan to change any of these subdomains in the near future. Why would we . System is working fine for years with this setup 
Of course, you only need to set up these subdomains if you really use them.
Hope that helps ?
It’s restricting and doesn’t make sense. Why not require user (me) to add each CNAME individually? There are only 6 CNAMES required but by requiring sitejet users to use wildcard it prevents other CNAMES from being used.
I am not sure, if I understood your reply correctly. There is no “restriction” from our side:
If you do not want to set a Wildcard CNAME or are not able to do so because your domain provider declines, then you can just set up a usual CNAME for your domain.
It is just easier to set the wildcard CNAME and makes possible transitions easier in the future. If you do not want to use the other subdomains and dislike the wildcard, then don’t do it?
It is restricting because it is a feature the requires total submission. Why does sitejet require control over allowing me to use any CNAME on my domain?
When you say, “if you don’t like, don’t do it.” That’s cool and I understand. But it is a feature that users want and that is a high level and advanced feature; why require total submission from advanced users? Using a wildcard is useful for users who aren’t aware of the restrictions.
It’s easier for Sitejet. Right? Is that what you are saying? It’s easier for sitejet to take complete control of a user’s domain? That may be true but that’s not making it easier for the user. I think it’s important to provide what user wants, not what we think the user wants.
Thank you for your comment on this - I think I can just repeat myself, unfortunately.
On this matter, we provide many ways on how to use the whitelabel-feature 
There is no restriction on this process. YOU can decide if you set up a CNAME for the whitelabel feature, and you can decide how to do that. We just offer a simple solution for both sides. Maybe that was not made clear beforehand.
If you are an advanced user that knows how to work with this, you are of course able and entitled to choose the “non-wildcard way” and just set up the subdomain you need 
Hope that helps.
Thanks for the quick response. Are there docs on the exact subdomains? I saw a list here on the forum but is that the official list?
You are very welcome This would be the subdomains you could use. 
Here are a few more details about the subdomains: How to use subdomains - Sitejet Help