#include<bits/stdc++.h>

using namespace std;

struct Node : public std::array<int, 26> {
    using std::array<int, 26>::array;

    Node operator+(const Node &y) const {
        Node ans;
        for(int i = 0; i < 26; i++) {
            ans[i] = (*this)[i] + y[i];
        }
        return ans;
    }

    Node operator-(const Node &y) const {
        Node ans;
        for(int i = 0; i < 26; i++) {
            ans[i] = (*this)[i] - y[i];
        }
        return ans;
    }

    Node operator*(const int x) const {
        Node ans = *this;
        for(int i = 0; i < 26; i++) {
            ans[i] *= x;
        }
        return ans;
    }

    bool isEmpty() const {
        for(int i = 0; i < 26; i++) {
            if((*this)[i] != 0) {
                return false;
            }
        }
        return true;
    }

    bool operator!=(const Node &y) const {
        if(this->isEmpty() || y.isEmpty()) {
            return false;
        } else {
            return !((*this) == y);
        }
    }

    bool operator>(const Node &y) {
        for(int i = 0; i < 26; i++) {
            if((*this)[i] < y[i]) {
                return false;
            }
        }
        return true;
    }

    bool operator<<(const Node &y) {
        if((*this) != y) {
            return false;
        }
        if(!y.isEmpty()) {
            (*this) = y;
        }
        return true;
    }
};

void assign_string(string &s, int l, int r, Node node) {
    int p = 0;
    for(int i = l; i <= r; i++) {
        while(p < 25 && node[p] == 0) {
            p++;
        }
        s[i] = (char)('a' + p);
        node[p]--;
    }
}

#define endl '\n'

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int T;
    cin >> T;
    while(T--) {
        int n;
        cin >> n;
        vector<string> s(n);
        vector<int> sz(n);
        vector<Node> cnt(n);
        vector<vector<Node>> cst(n);
        for(int i = 0; i < n; i++) {
            cin >> s[i];
            for(auto ch : s[i]) {
                cnt[i][ch - 'a']++;
            }
            sz[i] = s[i].size();
            cst[i].resize(s[i].size());
        }
        cst[0].back() = cnt[0];
        bool fl = true;
        for(int i = 1; i < n; i++) {
            for(int j = 0; j < s[i].size(); j++) {
                if(j < sz[i - 1]) {
                    cst[i][j] = cst[i - 1][j];
                } else if(!cst[i][j - sz[i - 1]].isEmpty()) {
                    cst[i][j] = cst[i][j - sz[i - 1]] + cnt[i - 1];
                }
            }
            if(cst[i].back() != cnt[i]) {
                fl = false;
                break;
            }
            cst[i].back() = cnt[i];
            if(sz[i] % sz[i - 1] != 0 && sz[i] > sz[i - 1]) {
                auto t = cnt[i] - cnt[i - 1] * (sz[i] / sz[i - 1]);
                if(t != cst[i][(sz[i] - 1) % sz[i - 1]]) {
                    fl = false;
                    break;
                } else {
                    cst[i][(sz[i] - 1) % sz[i - 1]] = t;
                }
            }
        }

        for(int i = n - 1; i > 0 && fl; i--) {
            for(int j = 0; j < sz[i] && fl; j++) {
                if(!cst[i][j].isEmpty()) {
                    fl = (fl && (cst[i - 1][j % sz[i - 1]] << (cst[i][j] - cnt[i - 1] * (j / sz[i - 1]))));
                }
            }
        }

        for(int i = 1; i < n && fl; i++) {
            for(int j = 0; j < s[i].size(); j++) {
                if(j < sz[i - 1]) {
                    if(cst[i - 1][j] != cst[i][j]) {
                        fl = false;
                        break;
                    } else if(!cst[i - 1][j].isEmpty()) {
                        cst[i][j] = cst[i - 1][j];
                    }
                } else if(!cst[i][j - sz[i - 1]].isEmpty()) {
                    auto t = cst[i][j - sz[i - 1]] + cnt[i - 1];
                    if(t != cst[i][j]) {
                        fl = false;
                        break;
                    } else if(!t.isEmpty()) {
                        cst[i][j] = t;
                    }
                }
            }
        }

        vector<string> ans = s;
        for(int i = 0; i < n; i++){
            int last = s[i].size() - 1;
            for(int j = s[i].size() - 2; j >= 0; j--) {
                if(!cst[i][j].isEmpty()) {
                    if(cst[i][last] > cst[i][j]) {
                        assign_string(ans[i], j + 1, last, cst[i][last] - cst[i][j]);
                        last = j;
                    } else {
                        fl = false;
                        break;
                    }
                }
            }
            assign_string(ans[i], 0, last, cst[i][last]);
        }
//        for(int i = 1; i < n && fl; i++) {
//            for(int j = 0; j  < sz[i]; j++) {
//                ans[i][j] = ans[i - 1][j % sz[i - 1]];
//            }
//        }

        if(fl) {
            cout << "YES" << endl;
            for(auto & str : ans) {
                cout << str << e

answer.code: In function ‘int main()’:
answer.code:183:32: error: ‘e’ was not declared in this scope
  183 |                 cout << str << e
      |                                ^
answer.code:183:33: error: expected ‘}’ at end of input
  183 |                 cout << str << e
      |                                 ^
answer.code:182:35: note: to match this ‘{’
  182 |             for(auto & str : ans) {
      |                                   ^
answer.code:183:33: error: expected ‘}’ at end of input
  183 |                 cout << str << e
      |                                 ^
answer.code:180:16: note: to match this ‘{’
  180 |         if(fl) {
      |                ^
answer.code:183:33: error: expected ‘}’ at end of input
  183 |                 cout << str << e
      |                                 ^
answer.code:88:16: note: to match this ‘{’
   88 |     while(T--) {
      |                ^
answer.code:183:33: error: expected ‘}’ at end of input
  183 |                 cout << str << e
      |                                 ^
answer.code:82:12: note: to match this ‘{’
   82 | int main() {
      |            ^