Function orders_after_topic_blocks 

pub(crate) fn orders_after_topic_blocks(
    tags: &[String],
    default_page: &str,
) -> bool

Whether a block with the author’s tags gets @order NaN (ORDER_AFTER_TOPIC_BLOCKS): it joins an author topic (joins_author_topic against default_page), the author did not order it with their own @order, and it renders a page (no @noRd).