I think i get it. If someone asks me to sign a message instead of just sending a message like [message] i should add something like [Form the desk of chriscross (and other identifiable details)]? Right?
The second warning i still don't get...
I think what he means is try to include details like, time and date payment was sent or details about what the payment is for.
However, i still do not fully understand the concept of this signing/verifying messages.
Say I send someone .32 BTC for 2 Eruptors listed from a group buy. The seller received my BTC as well as 35 other payments at around the same time and a lot of them are identical payments (.32BTC) as mine. Signing a message would tie my name to an address for the seller to create a "receipt" or at the least visually confirm that he is sending the items to the person that paid for them. Is this correct?
If I do not sign the message on my own, would the seller be able to request a signature message?