Sentence:  The solicitor acting for the vendor in one of these cases had cause to telephone the writer this afternoon to request an early date for exchange of contracts, and, upon being advised of the horror with which the writer had viewed the above clause, advised that she quite agreed with the views expressed, to whit that such a clause made mockery of the whole question of <WSD>preexchange</WSD> of contract enquiries, but said that this clause was now put into virtually all contracts prepared by Kent solicitors. 
Meaning of the word marked with <WSD> tags:  An exchange that takes place beforehand.