/*
  author: honglan0301
  Sexy_goodier _ xiaoqing
 */
#include <iostream>
#include <cstring>
#include <algorithm>
#include <cstdio>
#include <cctype>
#include <queue>
#include <map>
#include <unordered_map>
#include <cstdlib>
#include <ctime>
#include <vector>
#include <cmath>
#include <random>
#include <set>
#include <bitset>
#include <assert.h>
using namespace std;

//namespace Fread{const int SIZE=1<<20;char buf[SIZE],*S,*T;inline char getchar(){if(S==T){T=(S=buf)+fread(buf,1,SIZE,stdin);if(S==T)return'\n';}return*S++;}}using namespace Fread;namespace Fwrite{const int SIZE=1<<20;char buf[SIZE],*S=buf,*T=buf+SIZE;inline void flush(){fwrite(buf,1,S-buf,stdout);S=buf;}inline void putchar(char c){*S++=c;if(S==T)flush();}struct NTR{~NTR(){flush();}}ztr;}using namespace Fwrite;
//#define getchar Fread::getchar
//#define putchar Fwrite::putchar

namespace Fastio{struct Reader{template<typename T>Reader&operator>>(T&x){x=0;short f=1;char c=getchar();while(c<'0'||c>'9'){if(c=='-')f*=-1;c=getchar();}while(c>='0'&&c<='9')x=(x<<3)+(x<<1)+(c^48),c=getchar();x*=f;return*this;}Reader&operator>>(double&x){x=0;double t=0;short f=1,s=0;char c=getchar();while((c<'0'||c>'9')&&c!='.'){if(c=='-')f*=-1;c=getchar();}while(c>='0'&&c<='9'&&c!='.')x=x*10+(c^48),c=getchar();if(c=='.')c=getchar();else{x*=f;return*this;}while(c>='0'&&c<='9')t=t*10+(c^48),s++,c=getchar();while(s--)t/=10.0;x=(x+t)*f;return*this;}Reader&operator>>(long double&x){x=0;long double t=0;short f=1,s=0;char c=getchar();while((c<'0'||c>'9')&&c!='.'){if(c=='-')f*=-1;c=getchar();}while(c>='0'&&c<='9'&&c!='.')x=x*10+(c^48),c=getchar();if(c=='.')c=getchar();else{x*=f;return*this;}while(c>='0'&&c<='9')t=t*10+(c^48),s++,c=getchar();while(s--)t/=10.0;x=(x+t)*f;return*this;}Reader&operator>>(__float128&x){x=0;__float128 t=0;short f=1,s=0;char c=getchar();while((c<'0'||c>'9')&&c!='.'){if(c=='-')f*=-1;c=getchar();}while(c>='0'&&c<='9'&&c!='.')x=x*10+(c^48),c=getchar();if(c=='.')c=getchar();else{x*=f;return*this;}while(c>='0'&&c<='9')t=t*10+(c^48),s++,c=getchar();while(s--)t/=10.0;x=(x+t)*f;return*this;}Reader&operator>>(char&c){c=getchar();while(c==' '||c=='\n'||c=='\r')c=getchar();return*this;}Reader&operator>>(char*str){int len=0;char c=getchar();while(c==' '||c=='\n'||c=='\r')c=getchar();while(c!=' '&&c!='\n'&&c!='\r')str[len++]=c,c=getchar();str[len]='\0';return*this;}Reader&operator>>(string&str){str.clear();char c=getchar();while(c==' '||c=='\n'||c=='\r')c=getchar();while(c!=' '&&c!='\n'&&c!='\r')str.push_back(c),c=getchar();return*this;}Reader(){}}cin;const char endl='\n';struct Writer{const int Setprecision=6;typedef int mxdouble;template<typename T>Writer&operator<<(T x){if(x==0){putchar('0');return*this;}if(x<0)putchar('-'),x=-x;static short sta[40];short top=0;while(x>0)sta[++top]=x%10,x/=10;while(top>0)putchar(sta[top]+'0'),top--;return*this;}Writer&operator<<(double x){if(x<0)putchar('-'),x=-x;mxdouble _=x;x-=(double)_;static short sta[40];short top=0;while(_>0)sta[++top]=_%10,_/=10;if(top==0)putchar('0');while(top>0)putchar(sta[top]+'0'),top--;putchar('.');for(int i=0;i<Setprecision;i++)x*=10;_=x;while(_>0)sta[++top]=_%10,_/=10;for(int i=0;i<Setprecision-top;i++)putchar('0');while(top>0)putchar(sta[top]+'0'),top--;return*this;}Writer&operator<<(long double x){if(x<0)putchar('-'),x=-x;mxdouble _=x;x-=(long double)_;static short sta[40];short top=0;while(_>0)sta[++top]=_%10,_/=10;if(top==0)putchar('0');while(top>0)putchar(sta[top]+'0'),top--;putchar('.');for(int i=0;i<Setprecision;i++)x*=10;_=x;while(_>0)sta[++top]=_%10,_/=10;for(int i=0;i<Setprecision-top;i++)putchar('0');while(top>0)putchar(sta[top]+'0'),top--;return*this;}Writer&operator<<(__float128 x){if(x<0)putchar('-'),x=-x;mxdouble _=x;x-=(__float128)_;static short sta[40];short top=0;while(_>0)sta[++top]=_%10,_/=10;if(top==0)putchar('0');while(top>0)putchar(sta[top]+'0'),top--;putchar('.');for(int i=0;i<Setprecision;i++)x*=10;_=x;while(_>0)sta[++top]=_%10,_/=10;for(int i=0;i<Setprecision-top;i++)putchar('0');while(top>0)putchar(sta[top]+'0'),top--;return*this;}Writer&operator<<(char c){putchar(c);return*this;}Writer&operator<<(char*str){int cur=0;while(str[cur])putchar(str[cur++]);return*this;}Writer&operator<<(const char*str){int cur=0;while(str[cur])putchar(str[cur++]);return*this;}Writer&operator<<(string str){int st=0,ed=str.size();while(st<ed)putchar(str[st++]);return*this;}Writer(){}}cout;}using namespace Fastio;
#define cin Fastio::cin
#define cout Fastio::cout
#define endl Fastio::endl//;fflush(stdout)
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define mod 1000000007
mt19937 rnd(time(0));
mt19937_64 rndl(time(0));

int T,n;
string s[100005],t[100005];

struct dat
{
	int cnt[26];
	void init() {memset(cnt,0,sizeof(cnt));}
	friend dat operator+(dat x,dat y) {dat z; for(int i=0;i<26;i++) z.cnt[i]=x.cnt[i]+y.cnt[i]; return z;}
	friend dat operator-(dat x,dat y) {dat z; for(int i=0;i<26;i++) z.cnt[i]=x.cnt[i]-y.cnt[i]; return z;}
	friend dat operator*(dat x,int y) {dat z; for(int i=0;i<26;i++) z.cnt[i]=x.cnt[i]*y; return z;}
	int ok() {for(int i=0;i<26;i++) if(cnt[i]<0) return 0; return 1;}
}qq[100005];

vector <pair<int,dat>> ld,nd;
bool cmp(pair<int,dat> xx,pair<int,dat> yy) {return xx.fi<yy.fi;}

string calc(dat x)
{
	string na;
	for(int i=0;i<26;i++) for(int j=1;j<=x.cnt[i];j++) na+=(char)('a'+i); return na;
}

dat nr[5000005];
int vis[5000005];
int equ(dat x,dat y)
{
	for(int i=0;i<26;i++) if(x.cnt[i]!=y.cnt[i]) return 0; return 1;
}

signed main()
{
	cin>>T;
	while(T--)
	{
		cin>>n;
		for(int i=1;i<=n;i++) 
		{
			cin>>s[i]; qq[i].init(); for(int j=0;j<s[i].length();j++) qq[i].cnt[s[i][j]-'a']++;
		}
		nd.clear(); ld.clear();
		nd.pb(mp(s[n].length(),qq[n]));
		int flag=1;
		for(int i=n-1;i>=1;i--)
		{
			swap(ld,nd); nd.clear(); 
			nd.pb(mp(s[i].length(),qq[i]));
			for(int j=0;j<=s[i].length();j++) vis[j]=0; vis[s[i].length()]=1; nr[s[i].length()]=qq[i];
			for(auto j:ld)
			{
				int llen=j.fi; dat lcc=j.se;
				int tlen=llen%s[i].length(); dat tdat=lcc-(qq[i]*(llen/s[i].length()));
				if(!vis[tlen]) vis[tlen]=1,nr[tlen]=tdat,nd.pb(mp(tlen,tdat));
				else if(!equ(tdat,nr[tlen])) flag=0;
			}
		}
		sort(nd.begin(),nd.end(),cmp);
		if(!nd[0].se.ok()) flag=0;
		for(int i=1;i<nd.size();i++) if(!(nd[i].se-nd[i-1].se).ok()) flag=0;
		if(!flag) {cout<<"NO"<<endl; continue;}
		cout<<"YES"<<endl;
		t[1]=""; t[1]+=calc(nd[0].se); for(int i=1;i<nd.size();i++) t[1]+=calc(nd[i].se-nd[i-1].se);
		for(int i=2;i<=n;i++)
		{
			t[i]="";
			for(int j=0;j<s[i].length();j++) t[i]+=t[i-1][j%s[i-1].length()];
		}
		for(int i=1;i<=n;i++) cout<<t[i]<<endl;
	}
}////