For enexprs(), ensyms() and enquos(), names of arguments to capture without evaluation (including ...). For exprs() and quos(), the expressions to capture unevaluated (including expressions contained in ...).

Whether to ensure all dots are named. Unnamed elements are processed with as_label() to build a default name.

Whether to ignore empty arguments. Can be one of "trailing", "none", "all". If "trailing", only the last argument is ignored if it is empty. Note that "trailing" applies only to arguments passed in ..., not to named arguments. On the other hand, "all" also applies to named arguments.