[Skimmer]

Do you want create commands with Parameters?
It's simple, if you use sscanf.

pawn Код:

CMD:akill(playerid,params[])
{
    new id; // We create a variable, to save target players ID.
    // Player has used the command /akill, but without params.
    if(sscanf(params, "u", id)) return SendClientMessage(playerid, 0xFF0000FF, "USAGE: /akill (playerid)");
    // We check is the target player connected or not.
    if(!IsPlayerConnected(id)) return SendClientMessage(playerid, 0xFF0000FF, "Player is not connected.");
    SetPlayerHealth(id, 0);
    return 1;
}

Here's an example again, but now with string and without sscanf.

pawn Код:

CMD:announce(playerid, params[])
{
    if(!strlen(params)) return SendClientMessage(playerid, 0xFF0000FF, "USAGE: /announce (text)");
    GameTextForAll(params, 4000, 3);
    return 1;
}