Is there a preferred way/standard on how to transmit an initialization vector for AES encryption Is there a preferred way on how to transmit the initiliazation vector with witch AES encryption was made? I could imagine that, if the encrypted data is stored to a file, the IV is preppended at the file's beginning before the actual encrypted data (or somehting similar).

Is there such a convention?
The most common way to transmit an initialization vector is, indeed, to prepend it immediately before the ciphertext.

When you look at the original ciphermodes the first used IVs (CBC, CFB, OFB), the IV actually does function as a 'previous ciphertext block' for the very first actual ciphertext block; placing it immediately in front of the very first ciphertext block makes more sense than any other alternative.

Now, for newer modes (such a CTR), the IV is used in other ways internally.  However, the convention stuck.