#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define elif else if
#define vi vector<int>
#define vll vector<ll>
#define vvi vector<vi>
#define pii pair<int,int>


#define repname(a, b, c, d, e, ...) e
#define rep(...)                    repname(__VA_ARGS__, rep3, rep2, rep1, rep0)(__VA_ARGS__)
#define rep0(x)                     for (int rep_counter = 0; rep_counter < (x); ++rep_counter)
#define rep1(i, x)                  for (int i = 0; i < (x); ++i)
#define rep2(i, l, r)               for (int i = (l); i < (r); ++i)
#define rep3(i, l, r, c)            for (int i = (l); i < (r); i += (c))





struct ScalarInput {
    template<class T>
    operator T(){
        T ret;
        cin >> ret;
        return ret;
    }
};
struct VectorInput {
    size_t n;
    VectorInput(size_t n): n(n) {}
    template<class T>
    operator vector<T>(){
        vector<T> ret(n);
        for(T &x : ret) cin >> x;
        return ret;
    }
};
ScalarInput input(){ return ScalarInput(); }
VectorInput input(size_t n){ return VectorInput(n); }

template<typename T>
void print(vector<T> a){
  for(int i=0;i<a.size();i++){
    cout<<a[i]<<" \n"[i+1==a.size()];
  }
}

template<class T>
void print(T x){
    cout << x << '\n';
}
 
template <class Head, class... Tail>
void print(Head&& head, Tail&&... tail){
  cout << head << ' ';
  print(forward<Tail>(tail)...);
}

using S26=array<int,26>;

void printS26(S26 x){
  rep(i,26)cout<<x[i]<<" ";
  cout<<endl;
}
void solve(){
  int N;
  cin>>N;
  vector<string>S(N);
  int mx=0;
  rep(i,N){
    cin>>S[i];
    mx=max(mx,(int)S[i].size());
  }
  S26 E26;
  rep(i,26)E26[i]=0;

  vector<int>sz(N);
  vector<vector<int>>A;
  vector<S26>memo(mx+1,E26);
  vector<int>seen(mx+1,0);
  rep(i,N){
    sz[i]=S[i].size();
    A.push_back({});
    A[i].resize(sz[i]);
    if(i==0){
      rep(j,(int)sz[i])A[i][j]=j;
    }
    else{
      rep(j,(int)sz[i])A[i][j]=A[i-1][j%sz[i-1]];
    }
    S26 rem=E26;
    rep(j,sz[i])rem[S[i][j]-'a']++;
    int L=0;
    for(int j=1;j<sz[i];j++){
      if(A[i][j]==0){
        rep(k,26)rem[k]-=memo[A[i][j-1]][k];
        L=i;
      }
    }
    rep(k,26){
      if(rem[k]<0){
        print("NO");
        return;
      }
    }

    int last=A[i][sz[i]-1];
    if(seen[last]==0){
      seen[last]=1;
      memo[last]=rem;
    }
    else{
      if(memo[last]!=rem){
        print("NO");
        return;
      }
    }
  }

  vector<int>wariate(mx);
  S26 tmp=E26;
  int idx=0;
  rep(i,mx){
    if(seen[i]==1){
      rep(k,26){
        if(tmp[k]>memo[i][k]){
          print("NO");
          return;
        }
        rep(memo[i][k]-tmp[k]){
          wariate[idx]=k;
          idx++;
        }
      }
      tmp=memo[i];
    }
  }
  print("YES");
  rep(i,N){
    string ans;
    for(auto j:A[i]){
      ans+='a'+wariate[j];
    }
    print(ans);
  }
}

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

  int T;
  cin>>T;
  rep(T)solve();
}