No, only alpha-numeric, underscore, dash and periods are allowed.
The URL property on pages is for path parameters (/). You cannot directly use query parameters (?) in here. Depending on what you need, you can use the OpenURL JavaScript action in Nanoflow Commons and then a JavaScript snippet to do something on the page with query parameters. An example of the JavaScript snippet for this use case could look like this:
const urlParams = new URLSearchParams(window.location.search);
if (urlParams.has('myParam')) {
const paramValue = urlParams.get('myParam');
if (paramValue === 'myValue') {
// Do the thing
}
}
Query parameters are currently supported for microflow URL's, but not for page URL's.
You could just use a microflow to show the page you want.