#include <bits/stdc++.h>
#pragma GCC optimize(2)
using namespace std;
namespace Bigcat {
template <typename T>
inline void max_s(T& a, const T& b) {
  a = max(a, b);
}
template <typename T>
inline void min_s(T& a, const T& b) {
  a = min(a, b);
}
template <typename T>
void sort_v(T& x) {
  sort(x.begin(), x.end());
}
template <typename T>
void erase_dup(T& x) {
  x.erase(unique(x.begin(), x.end()), x.end());
}
template <typename T, typename V>
int pos_l(const T& x, const V& v) {
  return lower_bound(x.begin(), x.end(), v) - x.begin();
}
template <typename T, typename V>
int pos_u(const T& x, const V& v) {
  return upper_bound(x.begin(), x.end(), v) - x.begin();
}
inline unsigned rand_g() {
  static mt19937 mt_rand((int)time(0));
  return mt_rand();
}
using LL = long long;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<LL>;
using PII = pair<int, int>;
using VPII = vector<PII>;
}  // namespace Bigcat
using namespace Bigcat;
const LL base = LL(1e9 + 7);
const LL INFL = 1LL << 62;
const int INF = 1 << 30;
const int MAX = int(2e3 + 100);
struct Node {
  int x, y, w;
};
bool operator<(const Node& n0, const Node& n1) { return n0.x < n1.y; }
string zm[MAX];
VPII zz[300];
int zr[300][4];
void solve1() {
  for (int i = 0; i < (int)(300); i++) zz[i].clear();
  LL result = 0;
  int n, m;
  cin >> n >> m;
  for (int i = 0; i < (int)(n); i++) {
    cin >> zm[i];
    for (int j = 0; j < (int)(m); j++) {
      zz[zm[i][j]].push_back({i + 1, j + 1});
    }
  }
  memset(zr, 0, sizeof(zr));
  int tr[4] = {0};
  for (char c = 'z'; c >= 'a'; --c) {
    if (zz[c].empty()) {
      memcpy(zr[c], tr, sizeof(tr));
      continue;
    }
    max_s(result, LL(c - 'a') + 1);
    auto& z0 = zz[c];
    int x0, y0, x1, y1;
    x1 = x0 = z0[0].first;
    y1 = y0 = z0[0].second;
    for (auto g : z0) {
      min_s(x0, g.first);
      min_s(y0, g.second);
      max_s(x1, g.first);
      max_s(y1, g.second);
    }
    if (x0 != x1 && y1 != y0) {
      cout << "NO\n";
      return;
    }
    for (int x = x0; x <= x1; ++x) {
      for (int y = y0; y <= y1; ++y) {
        char t = zm[x - 1][y - 1];
        if (t == '.' || t < c) {
          cout << "NO\n";
          return;
        }
      }
    }
    zr[c][0] = x0;
    zr[c][1] = y0;
    zr[c][2] = x1;
    zr[c][3] = y1;
    memcpy(tr, zr[c], sizeof(tr));
  }
  cout << "YES\n";
  cout << result << '\n';
  for (char c = 'a'; c <= 'z'; ++c) {
    if (zr[c][0] == 0) break;
    for (int i = 0; i < (int)(4); i++) {
      cout << zr[c][i] << ' ';
    }
    cout << '\n';
  }
}
const bool _multi_test = 1;
const int _inId = 1;
const int _outId = 0;
void io_init(char* s0) {
  string path(s0);
  int a = path.find("build\\");
  int b = path.find("Release\\");
  if (a > 0 && b > a) {
    path = path.substr(0, a) + path.substr(a + 6, b - a - 6);
  } else
    path = "";
  if (_inId > 0) {
    cerr << "redirect stdin to input " << _inId << endl;
    string s = "input";
    s += to_string(_inId);
    s += ".txt";
    if (path != "") s = path + s;
    auto r = freopen(s.c_str(), "r", stdin);
    if (r == nullptr) {
      cerr << "invalid input file " << s << endl;
      ;
      r = freopen("CON", "r", stdin);
    }
  }
  if (_outId > 0) {
    cerr << "redirect stdout to stdout " << _outId << endl;
    string s = "stdout";
    s += to_string(_outId);
    s += ".txt";
    if (path != "") s = path + s;
    auto r = freopen(s.c_str(), "w", stdout);
    if (r == nullptr) {
      cerr << "invalid output file " << s << endl;
      ;
      r = freopen("CON", "w", stdout);
    }
  }
}
const bool _local_test = false;
void solve() {
  int t = 1;
  if (_multi_test) cin >> t;
  if (_local_test) cerr << " now base " << base << endl;
  for (int i = 0; i < t; ++i) {
    if (_local_test) cerr << " tasks: " << i + 1 << endl;
    solve1();
  }
  int x = 1;
}
signed main(signed argc, char* argv[]) {
  if (_local_test) {
    if (argc == 1) {
      io_init(argv[0]);
    }
  }
  cin.sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin.exceptions(cin.failbit);
  cout.precision(11);
  solve();
}
