Constant APPEAL_EVIDENCE_DOC 

pub const APPEAL_EVIDENCE_DOC: &str = "Cite evidence by writing post or comment UUIDs \
     directly in the statement: every one is fetched and put before the court, so there is \
     no separate evidence field. At most 5, and each must resolve to a real post or comment \
     (removed content counts). A filing citing something that resolves to nothing is \
     refused, and the refusal names every problem at once.";

How file_appeal takes evidence: cited in the statement itself. For the REST docs; the tool says it in appeal_statement’s description