When do you use the ampersand in official document?

The ampersand (&) is typically used in official documents when it is part of a formal name or title, such as in company names (e.g., Johnson & Johnson) or in legal citations. It is also acceptable in citations, references, or when space is limited, such as in tables or charts. However, in most formal writing, it's preferable to use "and" instead of the ampersand unless specified otherwise. Always consider the document's style guide for specific usage rules.