Final answer:
No, the red "C" in the corner is not always required when filing a document.
Step-by-step explanation:
No, you don't always have to file with the red "C" in the corner. The red "C" is the copyright symbol and it typically applies to creative works that are protected under copyright law. For example, if you are submitting an original piece of artwork or a written work that you have created, adding the copyright symbol can help indicate that you are claiming ownership of the work. However, not all documents require the use of the copyright symbol. It is important to consult the specific laws and regulations of your country or jurisdiction to determine when and how to properly use the copyright symbol.