Function key_argument_command 

pub fn key_argument_command(name: &str) -> bool

Whether name is a command whose arguments hold opaque keys, identifiers, or text rather than typeset math — the \label/\ref/\cite/\gls/color families plus \tag (amsmath, text content) and \hyperref (key plus link text). The union of the family predicates above, kept here so the name sets stay single-sourced; shared with the linter’s key-argument gate (crate::linter::rules::in_key_argument), which uses it to keep identifier keys like \label{eq:thing_max} out of the math-shape rules’ scope.