A good departmental policy describes a strategy for meeting pupils' special educational needs within the particular curricular area. It is not just a document you have ready for when an inspector calls. The process of getting staff together to clarify and evaluate current ideas and practice within the ICT team is far more important than the resultant piece of paper. It gives everyone a chance to reflect on what they are trying to achieve and to establish a consistent approach.
The starting point will be the school's SEN policy as required by the Education Act 1996, with each subject department ‘fleshing out’ the detail in a way which describes how things work in practice. The policy should establish:
the curriculum and how it can be differentiated
who is responsible for which areas
arrangements for assessment and reporting
staff with specialist training and/or knowledge
guidelines for working effectively with support staff
staff training needs