The attached documents explain a new update for SPLS which will be applicable from May 2006.
Administering Authority SPLS Upload news
From 15 May 2006 onwards, ODPM will be introducing some additional validation checks as part of the SPLS upload process. The purpose of these checks is to improve the quality of the data submitted by Administering Authorities (AAs) to ODPM.
To help with this process, ODPM will be making a test version of the upload system that includes the new rules available from 3 April onwards. AAs can use this to begin submitting test extracts against the new validation rules prior to the beginning of the next upload process on 15 May.
The link below explains further.
AA SPLS upload news