# IMSI - The IMSI is a unique identifier that is used to identify the subscriber on the network. It consists of a Mobile Country Code (MCC), Mobile Network Code (MNC), and Mobile Station Identification Number (MSIN). The MCC and MNC are used to identify the network operator, while the MSIN is used to identify the subscriber within the network. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://sim-cards.learn-telecom.com/gsm-identifiers/imsi.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.