This is what I saw on the USCIS website:
When the customer requests service by calling theNational Customer Service Center (NCSC) toll-free telephone number, a SRMT Service Request is created by NCSC staff if the inquiry cannot be resolved during the call. Though the majority of SRMTs are created at the NCSC, SRMTs are also created by officers, often when access to an A-file is needed to properly respond to the applicant’s question and the file is located elsewhere. Creating an SRMT allows the customer to receive a response without having to return to the office in most instances.
By using an online portal, customers living in the United States may create a requestdirectly for change of address (COA) requests regarding most receipt types (excluding VAWA, T nonimmigrant, and U nonimmigrant applicants or petitioners). [1] Customers may also directly initiate SRMT inquiries online when certain pending applications or petitions are outside normal processing times.
