Louisiana Revised Statutes Tit. 13, § 3348. Oaths of joint co-parties

In all judicial proceedings, where two or more parties are joined in interest and are acting together as co-plaintiffs, co-defendants, co-intervenors, co-opponents or co-warrantors, co-movers, or co-parties of any sort, and where as such, they are or may hereafter be required to make oath, in order to take out any writ, summons, process or order, or any judgment or decree, or in order to file any motion, pleading or instrument of any description, it shall be sufficient if one only of such co-plaintiffs, co-defendants, co-intervenors, co-opponents, co-movers, co-warrantors, or co-parties of any sort, shall subscribe and swear to the affidavit prescribed.