#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#define debug(...) fprintf(stderr, ##__VA_ARGS__)
#else
#define debug(...) void(0)
#define endl '\n'
#endif
typedef long long LL;
void chk(bool expr) { if (!expr) throw -1; }
#undef assert
#define assert chk
int mian() {
  int n;
  cin >> n;
  typedef array<int, 26> Set;
  vector<Set> a(n);
  vector<int> len(n);
  for (int i = 0; i < n; i++) {
    string s;
    cin >> s;
    len[i] = s.size();
    a[i].fill(0);
    for (auto ch : s) a[i][ch - 'a'] += 1;
  }
  priority_queue<pair<int, shared_ptr<Set>>> q;
  for (int i = n - 1; i >= 0; i--) {
    while (!q.empty() && q.top().first >= len[i]) {
      int L = q.top().first;
      Set lim = *q.top().second; q.pop();
      if (L == len[i]) {
        assert(a[i] == lim);
        continue;
      }
      int k = L / len[i];
      for (int j = 0; j < 26; j++) lim[j] -= a[i][j] * k, assert(lim[j] >= 0);
      if (L % len[i]) q.emplace(L % len[i], make_shared<Set>(lim));
    }
    q.emplace(len[i], make_shared<Set>(a[i]));
  }
  vector<pair<int, shared_ptr<Set>>> limitations;
  while (!q.empty()) limitations.push_back(q.top()), q.pop();
  reverse(limitations.begin(), limitations.end());
  string ans = "";
  Set now;
  now.fill(0);
  for (auto elem : limitations) {
    int L = elem.first;
    Set lim = *elem.second;
    debug("L = %d, lim = {", L);
    for (int i = 0; i < 26; i++) debug("%d, ", lim[i]);
    debug("}\n");
    for (int i = 0; i < 26; i++) lim[i] -= now[i], assert(lim[i] >= 0);
    for (int i = 0; i < 26; i++) while (lim[i]--) ans += static_cast<char>(i + 'a'), ++now[i];
  }
  cout << "YES" << endl;
  cout << ans << endl;
  for (int i = 1; i < n; i++) {
    string tmp(len[i], '\0');
    for (int j = 0; j < len[i]; j++) tmp[j] = ans[j % ans.size()];
    cout << (ans = tmp) << endl;
  }
  return 0;
}
int main() {
  cin.tie(nullptr)->sync_with_stdio(false);  
  int t;
  cin >> t;
  while (t--) try { mian(); } catch (...) { cout << "NO" << endl; }
  return 0;
}