Hey Daniel, thanks for your great plugin. I added the snippet to functions.php, and it throws following debug info: “Notice: Constant COAUTHORS_DEFAULT_BETWEEN_LAST already defined in …/functions.php on line …”. Also, adding the snippet didn’t change the default “and”.
Furthermore, I localized the plugin with poedit and translations work fine in admin, but don’t seem to take effect on the front (i.e. it doesn’t seem to translate the __( ' and ' ) ). FYI: I wrapped the coauthors_posts_links() template tag in a custom function like e.g. my_author_posts_links().