
It seems Adelaide Distributor of Stamps ran out of 30c stamps early in the week when the letter rate increased to $1 on 4 January 2016. To alleviate the shortfall the Adelaide GPO printed up an unknown quantity of 30c Counter-Printed Stamps with 'Adelaide 2016' literal.
These were distributed to Adelaide metropolitan corporate post shops that reordered 30c stamps that week and these Corporates also re-distributed supplies to LPOs in their immediate area.
I first saw them at my local post office but the postal manager would only let me buy three sets due to the shortage.
I put two sets on cover to mark the issue and kept a set mint.

I am advised by the Postal Manager at Adelaide GPO that this issue is deemed to be a retail product, and NOT a philatelic product, and therefore No FDI covers have, or will be, produced.
He also advises that distribution began on 5th January to 'a limited number of outlets' so earliest potential sale date is 6th January as offices received and started selling their stock.
Supplies of 30c stamps were back in the stocks of the Adelaide Distributor by Friday 8th January, and no more counter-printed stamps will be produced.
To reinforce the treatment as retail products the stamps were distributed in packs of 100 stamps usually made up of strips of five as they are easier to count.
Adelaide GPO had them in strips of five or ten and the more collectable strips of six could only be sourced from those strips of ten. As distribution was only to offices that ran out of 30c stamps during a four day period only they will be worth chasing.
It will be worthwhile recording where stamps have appeared. I saw them at Torrensville, and the Adelaide GPO. I visited Gawler PO on Saturday 9th to be told they had them but had sold out.
One of the local club members did a 'post office crawl' through the western and southern suburbs of Adelaide but the story was much the same. They either never got them, or had sold out.
Other offices known to have received supplies are Salisbury, Brighton, Glenelg, Hove, Oaklands Park, Pasadena, Burnside, West Lakes and Port Adelaide and all have sold out.
For those of you lucky enough to deal with kiloware and office mail please keep an eye out for these stamps and try to retain them on original cover. After my tip-off one of the local collectors did just that and returned a very few used examples - the earliest of which was postmarked on the 6th January. I would regard this as the earliest possible date of use.

I can confirm that the 'Adelaide 2016' literal has not been produced in any other denominations .... yet.
Who says modern issues are boring?!
Martin