If Variable Length Request is set to Y, the address supplied in Request Pointer points to a two-byte length (in binary) field which precedes the text of the request, and the length of the request text is not supplied in Request Length. The length provided preceding the text measures only the length of the request text, and does not include the two bytes of its own length. This introduces a limit on the length of the requests that can be sent using this method to 64K. No changes are done to increase this limit as this option exists is for PL/I, whose VARCHAR-like things start with the 2byte prefix. PL/I doesn't have any 4byte prefixes yet.