SSI use between two sites (looking for help)

I have multiple websites that contain unique/specific content. Their specific content will remain that way. In addition, I’d like to offer some cross-promotion between the MANY sites. I’ve been using SSI for years pulling header, footer, navigation elements into many pages contained within one website, so I have a basic understanding of <!–#include virtual=“/includes/file.html” –>, .html vs .shtml.

How do I use an include file at the root of one domain (site #1), call and embed the the necessary language from another website file (site #2) to include the content from the include at site #1?

Is this .htaccess permission related? How should the include code be written? Is this possible with includes?

Thanks for any suggestions. Let me know if I’m not explaining properly.

I am not sure SSI allows that but PHP probably does, I was getting a little lost what was being pulled from where into what? Though for cross-domain includes PHP is a more suitable answer and it is not much harder to write a PHP include.

Thanks for the reply and suggestion of using PHP include alternative. I will look into this solution.

Perhaps I made the initial example too complex. I’d still like to get an answer to whether or not SSI can be used between multiple web sites? How can one website hold content and be shared via SSI to other websites?

thanks again for any insight!

From Apache manual:

The include element can determine what file to include with either the file attribute, or the virtual attribute. The file attribute is a file path, relative to the current directory. That means that it cannot be an absolute file path (starting with /), nor can it contain …/ as part of that path. The virtual attribute is probably more useful, and should specify a URL relative to the document being served. It can start with a /, but must be on the same server as the file being served. [emphasis added]