How to distinguish between /modules.html and /index.html inside theme rendering context?

[balthild]

/index.html contains the README section but /modules.html does not. However, during the rendering of both pages, I cannot reliably distinguish them with PageEvent. Both have the url being index.html. The only difference is pageHeadings, which I don't think relying on it is a good idea because some project may have no README.