I'm looking at making a plugin that lists all of a user's questions and answers. I can set up a basic page at a URL like /user-activity. However if I try to open a page like /user-activity/DisgruntledGoat (i.e. for a specific user) I get a "page not found" error.
What is the answer here? Is the only way to use GET parameters like /user-activity?user=DisgruntledGoat ??