Wallet addresses?

[Bitgran]

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[therobotswillwin]

Different currencies have different prefixes.  I assume it's based on part of the encryption algorithm, but don't know for sure.  All of the addresses for a single coin share the same prefix from what I have seen.

[tompa555]

every coin address starts with first letter. like doge, starts with D********. I think only BitCoin don't have such rule. go to https://www.cryptsy.com there you can see all coins with their symbols. Their tree letters to be correct.

[DannyHamilton]

The format of a crypto-currency address is entirely up to the choice of the creators of that crypto-currency.

Many of the creators of various alt-coins have chosen to use a format similar to bitcoin, but with a different starting character (or set of characters) so that they won't be confused with bitcoin addresses (or the addresses of other alt-coins).

If I recall correctly, bitcoin has 2 different types of addresses that it supports right now. It uses a different starting character to differentiate between the 2 types of addresses.  The standard single signature address always starts with a 1.  I think if you create a multi-sig address, then it starts with a 3, but I could be mistaken.

[Picoin]

Yeah, altcoin dev's can use the prefix they like.