Essentially, the SENCO Guide 1997 was rendered out of date by the introduction, from January 2002, of the SEN Code of Practice and of an SEN Toolkit which gives schools (including SENCOs) and local authorities guidance on implementing the new code. 

These can be viewed/downloaded from the SEN website or ordered free of charge from DCSF online publications. Please quote reference 581/2001 for the code, 558/2001 for the toolkit.