1. What is [ANN] and 2. Double spends: First tx without a fee. 2nd tx with one.

[tjohej]

Question No. 1: what does [ANN] mean when added to topics?

Question No. 2(Short version)

If there is no fee at all the transfer can get a very low priority and take hours or even days to be included in a block.

How long and if it isn't included for 3 months will it stay there indefinitely until a miner includes it? If a miner does not include it is there anything the one owning the coins can do about it or are they lost? (until some miner accepts them, sry for repeating myself)

Question No. 2(Long version) Let's assume that now Bitcoin is 100% mainstream(let's imagine also in this example that all governments have abandoned their currencies and replaced them with Bitcoin) and that it is very unlikely that transactions can be sent for free anymore. If you send with a 0BTC tx fee then you'll have to wait at least 2 months until the money arrive or get rejected by the network for taking too long to be processed.

So, is there a time limit for how long a transaction that has not yet been spent stays in the Bitcoin transaction sharing P2P network?
If we assume I sent 0.01 BTC to a friend with a 0 transaction fee and that that amount of money has not yet arrived for 2 weeks because no miner wishes to include my transaction, can I add a fee to the same 0.01 BTC that later can be included by a miner if they wish to do it?

If I was not clear, I'm sorry, and please tell me and I'll try to rephrase my questions and examples. Thanks in advance!

[Kruncha]

1. [ANN] = announcement

2. I believe if a transaction isn't added to the blockchain within 48hours it is sent back to your wallet (not 100% on that one)

K.

[tjohej]

2. I believe if a transaction isn't added to the blockchain within 48hours it is sent back to your wallet (not 100% on that one)

Wow, thx. It would be awesome if somebody knows if this is correct or if something else is true

[tjohej]

by going to #bitcoin on Freenode I got my answer.

transactions will stay in each node's temporary memory until the node is restarted, in which case the transaction is erased from memory along with all transactions. That's how transactions are forgotten in the Bitcoin P2P network.

Haha, my question got answered! 

[redlight]

Double spend is a myth that will never happen.