The question mark (?) and ampersand (&) characters separate terms in a REST request. The first term in a request is the endpoint. A question mark always follows the endpoint. The question mark tells the Product Advertising API web servers to start parsing the request for parameters.
Ampersands separate all other parameter name-value pairs in the request. The order of parameter name-value pairs is unimportant, as long as they appear after the question mark.
You can combine multiple parameters in one batch request. The maximum number of characters in a request varies by browser. For example, the character limit for a URL in Internet Explorer is about 2000 characters. It is unusual for a request to meet this character limit.