I found a strange postscript in the URL in the metric, what is it?

Question

Nginx

I went into the metrics to look at the statistics on the site and saw strange endings in the URLs of the entry pages like /? What is it, any ideas?

Answer 1

Parameters passed by the GET method.
Why - no one will say without knowing what the site's engine is.

Answer 2

It's NOT about the website. Here we have a completely self-written engine and also in the last days we fix the URI parameter /? What is it - guess.