SECRET (i) Co-ordination within each Service Department. (ii) InterService liaison in all matters of joint interest. (c) By consultation with the Security branches of Service Departments concerned prior to ad hoc additional releases, it should sometimes be possible so to present the information as to avoid giving valuable data to a potential enemy. (d) Although by making the necessary effort it may be possible for a foreign power to collect various pieces of information which over a period of time ### ref cannot be concealed (such as the location of units).