-snip-
Here is the statement I am curious about:
On March 7, 2014, Mt.Gox Co., Ltd. confirmed that an old-format wallet which was used prior to June 2011 held a balance of approximately 200,000 BTC," the statement said. As reported CNN money -
Must be talking about 2011 version of Bitcoin Core or its wallet.dat since the article was written in 2014.
Or sometimes, users tend to use the term "
wallet" when talking about "
address".
But that article isn't technical for you to overthink in the use of "
old format", the latest version still supports the old version's keys/coins if you're worried of backwards compatibility.