"5.1 Save as provided below, and save in the case of a Part 7 claim form without particulars of claim or a Part 8 claim form, each party must provide to all other parties at the same time as its statement of case an Initial Disclosure List of Documents that lists and is accompanied by copies of -- (1) the key documents on which it has relied (expressly or otherwise) in support of the claims or defences advanced in its statement of case (and including the documents referred to in that statement of case); and (2) the key documents that are necessary to enable the other parties to understand the claim or defence they have to meet. 5.2 This form of disclosure is known as 'Initial Disclosure'."