May 2

As to whether there is a distinction between correspondence from the World Centre that has been signed "The Universal House of Justice" and that signed on behalf of the Secretariat: In brief, the manner in which each of these letters is prepared depends upon the contents of the letter. Drafts of letters which contain newly formulated policies are consulted upon and approved during a meeting of the House of Justice; correspondence dealing with previously enunciated policies, or with matters of a routine nature, are prepared, as delegated by the House of Justice, by its Secretariat and initialed by at least the majority of the members of the House of Justice before being dispatched. All letters written over the signature of the Department of the Secretariat are authorized by the Universal House of Justice. 
(From a letter dated 22 October, 1996, written on behalf of the Universal House of Justice to an individual believer)