#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5; 

int n, cnt[26], _cnt[26]; 
string s[N]; 

void solve(void) {
    cin >> n; 
    for (int i = 0; i < n; ++i) cin >> s[i]; 
    vector<string> mp(s[0].size()); 
    mp[0] = s[0]; 
    vector<int> p; p.push_back(0); 
    for (int i = 1; i < n; ++i) {
        int m = s[i].size(), id = -1, u = -1, len = 0;
        memset(cnt, 0, sizeof cnt); 
        for (char x : s[i]) ++cnt[x - 'a']; 
        while (id == -1) {
            for (int x : p) {
                len += mp[x].size(); 
                if (len <= m) for (char c : mp[x]) if (!cnt[c - 'a']--) return cout << "NO\n", void(); // 无法凑成
                if (len >= m) { id = x; break; }
            }
        }
        if (len > m) { // 有限制
            string s1, s2; memset(_cnt, 0, sizeof _cnt); 
            for (char x : mp[id]) ++_cnt[x - 'a']; // 模式串
            for (int c = 0; c < 26; ++c) {
                for (int t = cnt[c]; t--; ) s1 += char(c + 'a'); 
                int t = _cnt[c] - cnt[c];
                if (t < 0) return cout << "NO\n", void(); 
                while (t--) s2 += char(c + 'a'); 
            }
            // s1 为 s[i] 多余的部分
            // s2 为补全 s1 的部分
            mp[id] = s1; 
            mp[u = id + s1.size()] = s2; 
        }
        vector<int> _p; len = 0;
        auto add = [&](int x) { len += mp[x].size(); _p.push_back(x); };
        while (len < m) { // 补全成 s[i]
            for (int x : p) {
                add(x); if (len == m) break; 
                if (u != -1 && x == id) add(u); 
            } 
        }
        swap(p, _p);
    }
    string ans;
    for (auto &x : mp) ans += x; 
    cout << "YES\n" << ans << "\n"; 
    for (int i = 1; i < n; ++i) {
        string now; 
        for (int j = 0; j < s[i].size(); ++j) now += ans[j % ans.size()]; 
        cout << (ans = now) << "\n";
    }
}

int main(void) {
    ios::sync_with_stdio(0); 
    int T; cin >> T; 
    while (T--) solve(); 
    return 0;
}