# Key Principles *** **Use Login as an authentication service** * Option 1: NRIC/FIN and UUID * Option 2: UUID only **UUID** * Instead of NRIC/FIN, digital services of businesses can use the Universally Unique Identifier (UUID) to uniquely identify a person **Provide non-Singpass alternative** * Provide support to customers who prefer to use a non-Singpass alternative **PDPA & Applicable Regulations/Legislation** * Protect, retain and transfer data retrieved according to the rules of the Personal Data Protection Act (PDPA), relevant industry regulations and applicable legislation * For collection of National Identification Numbers, refer to the advisory guidelines from PDPC [here](https://www.pdpc.gov.sg/-/media/Files/PDPC/PDF-Files/Advisory-Guidelines/Advisory-Guidelines-for-NRIC-Numbers---310818.pdf) **Use for lawful purposes** * Use of user credentials for lawful purposes only --- # 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://docs.developer.singpass.gov.sg/docs/products/singpass-login/key-principles.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.