What does the number in the OpenDocument path of SAP BusinessObjects REST API represent?

I’m working with the SAP BusinessObjects RESTful Web Service SDK, specifically the OpenDocument service, and I encountered a URL like the following:

http://192.168.1.8:8080/BOE/OpenDocument/1809071819/OpenDocument/opendoc/openDocument.jsp

My question is: What does the number "1809071819" in the path represent?

I’ve searched the official documentation and other online resources, but I couldn’t find a clear explanation. Is it a session identifier, a timestamp, or some other type of information related to BusinessObjects?

Has anyone encountered this kind of URL before and knows what the number means?

Thanks in advance for your help!