We put a line with tcm information in the head section of the html page.
Purpose is that Sitemanager & content people easier can find the page in content manager.
<head> <meta name="tcm-info" content="tcm:99-417519-64" /> ..
With DXA, the Publication Id is unknown. Model Id contains only that 417519.
It's possible to make a config value, but is there a value already for Publication Id?