// pass accepted problem on the round
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N=3e5+5;
const int iu=19;
#define fi first
#define se second
int n;
string s[N];
int f[226];
int sz;

int len[N];
vector<int>ch[N];
string res[N];
void dfs(int id){
	if(ch[id].empty()) return;
	res[id]="";
	for(auto c:ch[id]){
		dfs(c);
		res[id]+=res[c];
	}
}

bool solve(){
	cin >> n;
	for(int i=1; i<=n ;i++) cin >> s[i];
	while(sz>1){
		ch[sz].clear();
		len[sz]=0;
		res[sz]="";
		sz--;
	}
	sz=1;
	ch[1].clear();
	res[1]=s[1];
	len[1]=s[1].size();
	vector<int>seq,nseq;
	seq.push_back(1);
	for(int i=2; i<=n ;i++){
		int frog=s[i].size()%s[i-1].size();
		int rep=s[i].size()/s[i-1].size();
		for(int j='a'; j<='z' ;j++) f[j]=0;
		for(auto c:s[i]) f[c]++;
		for(auto c:s[i-1]){
			f[c]-=rep;
			if(f[c]<0) return false;
		}
		nseq.clear();
		int u=-1,v=-1,w=-1;
		if(frog!=0){
			int cum=0;
			for(auto c:seq){
				if(cum==frog) break;
				if(cum+len[c]>frog){
					int tar=frog-cum;
					sz+=2;
					for(auto d:res[c]){
						if(f[d]>0) f[d]--,len[sz-1]++,res[sz-1]+=d;
						else len[sz]++,res[sz]+=d;
					}
					if(len[sz-1]!=tar) return false;
					ch[c]={sz-1,sz};
					u=c,v=sz-1,w=sz;break;
				}
				else{
					for(auto d:res[c]){
						if(--f[d]<0) return false;
					}
					cum+=len[c];
				}
			}
		}
		for(int i=0; i<rep ;i++){
			for(auto c:seq){
				if(c==u){
					nseq.push_back(v);nseq.push_back(w);
				}
				else nseq.push_back(c);
			}
		}
		
		if(frog!=0){
			int cum=0;
			for(auto c:seq){
				if(cum==frog) break;
				if(cum+len[c]>frog){
					nseq.push_back(v);
					break;
				}
				else{
					if(c==u){
						nseq.push_back(v);nseq.push_back(w);
					}
					else nseq.push_back(c);
					cum+=len[c];
				}
			}
		}
		seq=nseq;
		/*cout << "DOING " << i << endl;
		for(auto c:seq) cout << c << ' ';
		cout << endl;*/
	}
	dfs(1);
	string ans=res[1];
	cout << "YES\n";
	cout << ans << '\n';
	for(int i=2; i<=n ;i++){
		string nans;
		for(int j=0; j<s[i].size() ;j++){
			nans+=ans[j%s[i-1].size()];
		}
		ans=nans;
		cout << ans << '\n';
	}
	return true;
}
int main(){
	ios::sync_with_stdio(false);cin.tie(0);
	int t;cin >> t;
	while(t--){
		if(!solve()) cout << "NO\n";
	}
}