The subject of the numeral obliterators of South Australia is one in which little apparent progress has been made since the pioneering article of Harry Heinecke which appeared in Philately from Australia in 1956, although the list presented then had many gaps and apparent errors. Hugh Campbell and Don Pearce have now redressed this situation and increased our knowledge of the South Australian numerals to a level comparable to that of the other Australian Colonies.
New information has been obtained largely from archival sources, especially the Government Gazettes and Post Office Guides, which included official lists of post office numbers. What has emerged is a practically complete picture of the original allocations, plus fairly certain knowledge of a number of re-allocations. In the process the first accurate list of the post offices of South Australia and their opening and closing dates (up to 1874, when the numerals ceased to be issued) has been provided.
As a collecting field South Australian numerals remains one of the most difficult. Of the 314 numbers issued, over 10% have yet to be seen, while over 18% are rated RRRR (one or two copies seen) and only 16% are common (more than 26 copies seen). Tying covers for most numbers have never been seen..
