A description of the multiphoton correction for SNOMAN versions earlier than 4_0288 is available on Manhattan, http://manhattan.sno.laurentian.ca/sno/ananoteb.nsf/URL/MANN-5PD9RA . The channel properties group should prepare a document which describes all of the changes leading up to SNOMAN version 5_0082, including a complete descprition of the multiphoton timing correction. Watch for this document in the spring of 2005!