If you are filing USCIS form I-485 and are a Haitian national looking for permanent residence in the US under HRIFA you will need to file USCIS form I-485 (Supplement C, Instructions for I-485, Supplement C, HRIFA) along with your form I-485. It is important to send your Supplement C and your form I-485 together. Supplement C cannot be filed separately; it contains important instructions needed for your application. It is important to only file if you are filing form I-485 and are applying for permanent residency as a Haitian national under HRIFA. You can file form I-485 and Supplement C even if you are in deportation, exclusion, or removal proceedings, but if you are facing such challenges you will need to file in a different location; consult the instructions for more details.