When your referring to DAC are you referring to the bitUSD, bitGold, bitGOOG, bitBond, bitMusic? Or are you referring to Bitshares PTS or AGS (I dont even know what Bitshares AGS is?)
You should shortcut this link. It's very handy with all the new ideas flying around.
http://bitshares.org/faq/It provides clear concise ~100 word descriptions of most if not all the concepts we're dealing with.
To answer this post: A DAC is a Distributed Autonomous Company. BitSharesX is a DAC of a derivatives exchange where BTSX are shares in the exchange, like owning shares in the NYSE.
AGS are Angle Shares. They were PTS and BTC donations to an "Angel Fund" that was used to bootstrap the company - pay for office space, developers, marketing, etc. It was a limited time round of public funding. Now when a DAC that honors the social contract is released there is a percentage, often 10%/10% allocated to PTS/AGS holders/donors the time of the snapshot (date/time of the genesis block).