List ID's

Hi ThereI don't understand exactly how this works. There are some gaps in the List lets show an example:4175 - G-Force (E)(M4)(BAHAMUT) Europe 686
4172 - Monster Mayhem Build and Battle (U)(SUXXORS) USA 2460
4170 - Berlitz My English Coach (E)(M5)(BAHAMUT) Europe 914First question:
So where are 4171, 4173 and 4174? Are they coming later?Second Question:
I coded a Picture downloader for all my ROM's and then i noticed there are some differences between some Sites / Countries.Example, i Download 4111.JPG but the Game is 4122 ... something.nds.Last question:
is there any standard ID counter? If not.. which one should i use? .. until 4000 the most id's are identically with graphics and other sites..sorry my bad english and thnx in advance

Seph knows more about it, but it does vary by site.Romulation has the most accurate numbering system though :)

Those ROMs were PREd on some obscure FTP site that no one knows about, so they are valid releases, but no one have them. They are just some Danish children's games though, so no they're not overly important.This has happened before as well, usually they show up eventually.