"Mr. Howe is correct in assuming that the 'Mobile N.W.D. Agency' launch service was primarily used for medical purposes and I intended to imply this in my earlier notes when I stated that the Government Dispenser was additionally appointed T.P. Agent. I agree that the code marks are very interesting and for some time past I have been working on them in an endeavour to discover where they were used. This is, however, not easy because of the limited number of known proving covers. There is no doubt that 'E.4C' and 'E.7C' were used at Belfield and Mahaicony respectively and I believe 'E.5C' was used at Mahaica. According to my reckoning there are 44 of these code marks of which I have so far been able to collect 38. One way in which the story of these marks may be solved is by recording all known copies as a supplement to the meagre official records available. Including my own copies I have so far recorded close on 300 of these strikes and would be glad if, through the medium of our Bulletin, members similarly interested would assist me by giving details of any of these marks in their possession."