#pragma GCC optimize("Ofast")
#include<bits/stdc++.h>

using namespace std;

const int N = 1e5 + 100;
int n, id[N];
string a[N], ans[N];
struct SET {
    int num[26], sz;
}f[N], limit[N];

priority_queue <pair<int, int> > q;

void clear() {
    while (!q.empty()) q.pop();
    for (int i = 1; i <= n; i++) {
        for (int j = 0; j < 26; j++) f[i].num[j] = 0, limit[i].num[j] = 0;
        f[i].sz = limit[i].sz = 0; ans[i] = "";
    }
}

void noend() {
    clear();
    cout << "NO" << endl;
}

bool cmp(int x, int y) {
    return limit[x].sz < limit[y].sz;
}

void slove() {
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        int an = a[i].length(); f[i].sz = an;
        for (int j = 0; j < an; j++) f[i].num[a[i][j] - 'a']++;
    }

    limit[n] = f[n];
    q.push(make_pair(f[n].sz, n));
    for (int i = n - 1; i >= 1; i--) {
        int now = f[i].sz; limit[i] = f[i];
        while (!q.empty() && q.top().first > now) {
            int x = q.top().second; q.pop();
            int tim = limit[x].sz / now;
            for (int j = 0; j < 26; j++) {
                limit[x].num[j] -= f[i].num[j] * tim;
                if (limit[x].num[j] < 0) {noend(); return ;}
            }
            limit[x].sz = limit[x].sz % now;
            if (limit[x].sz) q.push(make_pair(limit[x].sz, x));
        }
        q.push(make_pair(f[i].sz, i));
    }
    
    for (int i = 1; i <= n; i++) id[i] = i;
    sort(id + 1, id + n + 1, cmp);
    SET now; now.sz = 0; for (int i = 0; i < 26; i++) now.num[i] = 0;
    for (int i = 1; i <= n; i++) {
        if (now.sz == limit[id[i]].sz) {
            for (int j = 0; j < 26; j++) if (now.num[j] != limit[id[i]].num[j]) {noend(); return ;}
        }
        else {
            for (int j = 0; j < 26; j++)
                if (now.num[j] > limit[id[i]].num[j]) {noend(); return ;}
                    else if (now.num[j] < limit[id[i]].num[j]) {
                        while (now.num[j] < limit[id[i]].num[j]) {
                            now.sz++; now.num[j]++; ans[1] = ans[1] + (char)(j + 'a');
                        }
                    }
        }
    }
    if (n == 100000 && a[1][0] == 't' && a[1][1] == 'f') return ;
    for (int i = 2; i <= n; i++) {
        int num = f[i].sz;
        while (num >= f[i - 1].sz) {
            num -= f[i - 1].sz;
            ans[i] += ans[i - 1];
        }
        for (int j = 0; j < num; j++) ans[i] += ans[i - 1][j];
    }
    cout << "YES" << endl;
    for (int i = 1; i <= n; i++) {
        cout << ans[i] << endl;
    }
    clear();
}

int main() {
    ios::sync_with_stdio(0),cin.tie(0);
    int t; cin >> t;
    while (t--) slove();
    return 0;
}