[Goncho28]

You only need to add SendClientMessageToAll under the both formats! And you don't need both callbacks (OnPlayerCommandText), only one.

pawn Код:

public OnPlayerCommandText(playerid, cmdtext[])
{
    if (strcmp("/offduty", cmdtext, true, 5) == 0)
    {
            new string[128];
        SendClientMessage(playerid,0xFFFFFF,"You're now an off-duty cop.");
        format(string, sizeof(string), "%s [%d] is now an off-duty cop.", GetName(playerid), playerid, GetName(targetid), targetid, reason);
        SendClientMessageToAll(-1, string);
    }

    if (strcmp("/onduty", cmdtext, true, 5) == 0)
    {
            new string[128];
        SendClientMessage(playerid,0xFFFFFF,"You're now an on-duty cop.");
        format(string, sizeof(string), "%s [%d] is now an on-duty cop.", GetName(playerid), playerid, GetName(targetid), targetid, reason);
        SendClientMessageToAll(-1, string);
    }
    return 0;
}

You must not define a global string, you must make one for each format, regards!