Signing a note is an important legal responsibility that many individuals undertake for various reasons. When writing about this action, it's important to avoid using the same phrase repeatedly. Synonyms for "have signed a note for" include "endorsed," "guaranteed," "cosigned," "backed," "acknowledged," and "approved." Using these synonyms can add variety to your writing and make it more interesting for your readers. Whether you're writing a legal document, an academic paper, or a personal letter, using these different words can help you convey your message more effectively, and allow you to express the same idea in various ways.