#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int,int>pii;
typedef pair<ll,ll>pll;
typedef pair<ld,ld>pdd;
typedef pair<ll, pair<ll, ll> > plpair;
typedef vector<int> vi;
typedef vector<ll> vl;
#define endl '\n'
#define rep(i, a, b) for (ll i = (a); i <= (b); ++i)
#define per(i, a, b) for(ll i = (a); i >= (b); --i)
#define debug(x) cout<<#x<<": "<<x<<endl
#define lowbit(id) id & (-id)
#define fi first
#define sec second
#define lc id<<1
#define rc id<<1|1
#define sz(x) (int)(x).size()
#define all(t) (t).begin(), (t).end()
#define meh {cout<<"NO"<<endl;return;}
#define yay {cout<<"YES"<<endl;return;}
#define vin(v) for(auto&x:v)cin>>x;
#define print(v) for (auto x: v)cout<<x<<' ';cout<<endl;
#define sqrt(x) sqrtl(x)
#define State int
mt19937_64 rnd(chrono::steady_clock::now().time_since_epoch().count());
const ll N = 1e3 + 10;
const ll M = 2e3 + 5;
const int mod = 998244353;

struct node{
	int c[26] = {0};
};

ll d, ss;

void solve() {
	ss++;
	ll n, cur = 0;
	cin >> n;
	node s[n + 5], t;
	rep(i, 0, n) {
		rep(j, 0, 25) {
			s[i].c[j] = 0;
		}
	}
	ll tot = 0, siz[n + 5];
	siz[0] = 0;
	rep(i, 1, n) {
		string t;
		cin >> t;
		siz[i] = t.size();
		int b[26];
		rep(j, 0, 25) {
			b[j] = 0;
		}
		rep(j, 0, siz[i] - 1) {
			b[t[j] - 'a']++;
		}
		rep(j, 0, 25) {
			s[i].c[j] = b[j];
		}
		tot += siz[i];
//		debug(i);
//		rep(j, 0, 25) {
//			if(s[i].c[j]) {
//				cout << "("<<char('a' + j) << "" << s[i].c[j] << ""<<")";
//			}
//		}
//		cout << endl;
	}
	node a[tot + 5];
	rep(i, 0, tot + 2) {
		rep(j, 0, 25) {
			a[i].c[j] = 0;
		}
	}
	ll nxt[tot + 5];
	rep(i, 0, tot + 2) {
		nxt[i] = -1;
	}
	tot = 0;
	nxt[0] = -1;
	bool g = 1;
	per(i, n, 1) {
		cur = 0;
		ll cut = 0, be = 0;
		t = s[i];
		g = 1;
		while((!g && cur != -1) || (g && nxt[cur] != -1)) {
			if(g) cur = nxt[cur];
			g = 1;
			int f = 1;
			rep(j, 0, 25) {
				if(t.c[j] < a[cur].c[j]) {
					f = 0;
				}
			}
			if(f) {
				if(!be) {
					rep(j, 0, 25) {
						t.c[j] -= a[cur].c[j];
						if(t.c[j]) f = 0;
					}
				}
				else {
					rep(j, 0, 25) {
						if(t.c[j] != a[cur].c[j]) {
							f = 0;
						}
					}
					if(!f) {
						tot++;
						rep(j, 0, 25) {
							a[tot].c[j] = t.c[j] - a[cur].c[j];
							a[be].c[j] = a[cur].c[j];
						}
						nxt[tot] = nxt[be];
						nxt[be] = tot;
						be = nxt[be];	
						t = a[be];
					} 
				}
			}
			else {
				tot++;
				rep(j, 0, 25) {
					a[tot].c[j] = a[cur].c[j] - t.c[j];
					a[cur].c[j] = t.c[j];
					if(a[tot].c[j] < 0) {
						cout << "NO" << endl;
						return;
					}
				}
				nxt[tot] = nxt[cur];
				nxt[cur] = tot;
				if(!cut) {
					cut = cur;
					cur = nxt[cur];
//					debug(cur);
					g = 0;
					nxt[cut] = -1;
//					debug(cut);
				}
				if(nxt[be] == -1) be = 0;
				be = nxt[be];
				t = a[be];
			}
			if(f) {
				if(!cut) {
					cut = cur;
					cur = nxt[cur];
					g = 0;
					nxt[cut] = -1;
//					debug(cut);
				}
				if(nxt[be] == -1) be = 0;
				be = nxt[be];
				t = a[be];
			}
		}	
//		debug(cut);
//		cur = 0;
//		debug(i);
//		while(nxt[cur] != -1) {
//			cur = nxt[cur];
//			rep(j, 0, 25) {
//				rep(k, 1, a[cur].c[j]) {
//					cout << char('a' + j);
//				}
//			}
//			cout << "**";
//		}
//		cout << endl;
		if(i != 1) {
			t = s[i];
			ll g = siz[i] / siz[i - 1];
			ll must = 0;
			cur = 0;
			rep(j, 0, 25) {
				if(t.c[j] - g * s[i - 1].c[j] < 0) {
					cout << "NO" << endl;
					return;
				}
				t.c[j] -= g * s[i - 1].c[j];
				if(t.c[j]) must++;
			}
			while((nxt[cur] != -1) && must) {
				cur = nxt[cur];
				int f = 1;
				rep(j, 0, 25) {
					if(t.c[j] < a[cur].c[j]) {
						f = 0;
					}
				}
				if(f) {
					rep(j, 0, 25) {
						if(t.c[j] && (t.c[j] == a[cur].c[j])) must--;
						t.c[j] -= a[cur].c[j];
					}
				}
				else {
					tot++;
					must = 0;
					rep(j, 0, 25) {
						a[tot].c[j] = a[cur].c[j] - t.c[j];
						a[cur].c[j] = t.c[j];
						if(a[tot].c[j] < 0) {
							cout << "NO" << endl;
							return;
						}
					}
					nxt[tot] = nxt[cur];
					nxt[cur] = tot;
				}
			}
			if(must) {
				tot++;
				a[tot] = t;
				nxt[tot] = nxt[cur];
				nxt[cur] = tot;
			}
		}
//		cur = 0;
//		if(d == 100 && i == 4 && ss == 22) {
//			cout << "YES" << endl;
//			debug(i);
//			cur = 0;
//			while(nxt[cur] != -1) {
//				cur = nxt[cur];
//				rep(j, 0, 25) {
//					if(a[cur].c[j])
//					cout << "("<<char('a' + j) << "" << a[cur].c[j] << ""<<")";
//				}
//				cout << "||";
//			}
//			cout << endl;
//		}
	}
	cout << "YES" << endl;
	string ans[n + 5];
	rep(i, 1, n) {
		ans[i] = "";
	}
	rep(i, 1, n) {
		ll cur = 0;
		if(i == 1) {
			t = s[i];
			ll must = 0;
			rep(j, 0, 25) {
				if(t.c[j]) must++;
			}
			while(nxt[cur] != -1) {
				cur = nxt[cur];
				rep(j, 0, 25) {
					rep(k, 1, min(a[cur].c[j], t.c[j])) {
						ans[i] += (char)('a' + j);
					}
					if(t.c[j] && (t.c[j] <= a[cur].c[j])) must--;
					t.c[j] -= a[cur].c[j];
				}
				if(!must) break;
			}
			rep(j, 0, 25) {
				rep(k, 1, t.c[j]) {
					ans[i] += (char)('a' + j);	
				}
			}
		}
		else {
			t = s[i];
			ll g = siz[i] / siz[i - 1];
			rep(j, 1, g) {
				ans[i] += ans[i - 1];
			}
			ll must = 0;
			rep(j, 0, 25) {
				t.c[j] -= s[i - 1].c[j] * g;
				must += t.c[j];
			}
			rep(k, 1, must) {
				ans[i] += ans[i - 1][k - 1];
			}
		}
	}
	rep(i, 1, n) {
//		if(d == 100 && i == 1 && ss == 4) {
//			cout << "||";
//			rep(j, 0, 25) {
//				rep(k, 1, s[i].c[j]) {
//					cout << (char)('a' + j);
//				}
//			}
//			cout << endl;
//		}
		node check;
		rep(j, 0, (int)ans[i].size() - 1) {
			check.c[ans[i][j] - 'a']++;
		}
		bool f = 0;
		rep(j, 0, 25) {
			if(check.c[j] != s[i].c[j]) {
				f = 1;
				cout << "||" << char('a' + j) << "||" << s[i].c[j] << "||" << check.c[j] << "||";
			}
		}
		if(f) cout << i << "|||||||||||";
		cout << ans[i] << endl;
	}
}

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int T = 1;
	cin >> T;
	d = T;
	//	cout.flush();
	//			ofstream outfile("C:\\Users\\86187\\OneDrive\\桌面\\1.txt");
	//		outfile << "a[1]=0;a[2]=1;";
	//		ll l = 1e7 + 1;
	//		rep(i, 3, 1e9) {
	//			printf("%lld\n", i);
	//			ll x = (i - 1) * ((a[i - 1] + a[i - 2]) % mod);
	//			x %= mod;
	//			if(i == l) {
	//				outfile << "a[" << i << "]=" << x << ";";
	//			}
	//			if(i == l + 1) {
	//				outfile << "a[" << i << "]=" << x << ";";
	//				l += 1e7;
	//			}
	//		}
	while(T--) {
		solve();
	}
	return 0;
}