At our meeting in October we agreed to send this proposal to the GRRF 81 as an informal document. This agreement was subject to any important information being brought up to this meeting. Since our October meeting Mr. Westphäling had requested RDW for any measurement values that possibly had been made in The Netherlands. Mr. Stokreef responded to that request saying that there was no measurement data available. However in some correspondence from 1982 some recommendations were found. Mr. Svensson commented those in the light of that many measurements had been made in Australia during the late eighties and even more just the last couple of years in Sweden. The foundation for our proposal is well good and sound. It is not affected by the comments from 1982. Hence it was decided to proceed with the informal document to the GRRF 81.