Function format_help_section 

pub fn format_help_section(
    fields: &[FieldInfo],
    default_fields: &[&str],
) -> String

Formats compact field summaries for command long help.

default_fields lists the field names shown when --fields is absent (see CommandSpec::with_default_fields); each one is marked (default) in the listing. The command’s --fields flag itself also carries this as a native clap [default: ...] (see command_clap_command_with_schema_help in cli.rs), so this marker is a per-field cross-reference rather than the only place the default appears. Pass an empty slice when the command has no default projection.

--filter/--expr usage examples used to live in a standalone section appended here; they now live on the --filter and --expr flags themselves (see apply_filter_and_expr_examples in cli.rs), the same way --fields carries its default natively instead of in prose.