No, call signs were not introduced until Modern Warfare 2.
no because once you go online you will start back from level 1. no emblem, no callsign, no unlocked guns.
when you get to a high enough level, go to Clan Tag in the Callsign and Killstreak selection in lobby
Modern Warfare Mobilized(the DS port of Modern Warfare 1) & Modern Warfare 3.
Modern warfare 1 or 2?
Get Modern Warfare 2.
go to call of duty wiki, highlight over modern warefare 2 and click on callsigns. once you done that scroll down and look for the callsign you want ;P
Modern Warfare 2 is better. It has improved guns and better graphics. It was also better promoted than Modern Warfare 1.
Modern Warfare is 2 player.
If u want to get MW2 title on online u reach lvl 5 or sumthing after u prestige TWICE!
When in a lobby or when you are at the multiplayer menus, go to callsign, select emblems and you should find the emblems that you have unlocked. The ones that have a green "NEW" above it are ones that you have not checked out yet.
The first modern warfare is an amazing game and i suggest you buy it if your thinking about not.
This is not possible - This is possible with a mod on modern warfare 2, but not modern warfare 1.