const boarders = [];
const usernames = [];

for (let i in reach.var.d.c) {
    const boarder = reach.var.d.c[i];

    if (security.specificContactCan(boarder, "BE_BOARDER")) {
        boarders.push(boarder);
    }
}

for (let i = 0; i < boarders.length; i++) {
    const boarder = boarders[i];

    usernames.push(boarder.un);
}

usernames.sort(function(a, b) {
    const aUsername = a.toLowerCase();
    const bUsername = b.toLowerCase();

    if (aUsername < bUsername) {
        return -1;
    } else if (aUsername == bUsername) {
        return 0;
    } else {
        return 1;
    }
}).reverse();

console.log(usernames);