Proposal and Rogatory Sentence

While the classification of the Proposition as a 'declarative' sentence is easy, the Proposal belongs to no obvious class.  The difficulty is well-illustrated by the status of the marriage variety, which is unarguably characterizable as a 'request'.  Now, requests are conventionally classified as 'imperative' sentences, which seems inaccurate, because a request is crucially not a command, even when the latter is tempered by the 'hypothetical' qualification, or as Searle's less forceful 'directive'.  For, what is lost in those classifications is the questioning dimension of a request.  On the other hand, 'interrogative' sentences seek information, not action.  However, there is an alternative--the obscure, but precise, 'rogatory'.  Put otherwise, communication is rogatory because, regardless of content, it fundamentally seeks a response, beginning with simply being attended to, and the Proposal is the basic sentential signal.