diff --git a/README.md b/README.md
index a7e539edba2a300a4763232128052193d7115450..b574e15aeef762c49bc15cfe58168b3c67905902 100644
--- a/README.md
+++ b/README.md
@@ -49,19 +49,19 @@ The `csst_proto` uses an awesome algorithm based on `numpy.ndarray` indices to f
 
 ## timeline
 
-| file / directory   | description                     | notes | C6  | C7  |
-|--------------------|---------------------------------|-------|-----|-----|
-| `csst_proto/`      | source code & data              |       | √   |     |
-| `doc/`             | sphinx-based documentation      |       |     | √   |
-| `example/`         | code examples                   |       | -   | -   |
-| `tests/`           | unit tests                      |       |     | √   |
-| `.gitignore`       | git file                        |       | √   |     |
-| `.gitlab-ci.yml`   | gitlab CI/CD pipeline           |       |     | √   |
-| `LICENSE`          | code license                    |       | √   |     |
-| `README.md`        | readme file                     |       | √   |     |
-| `install.sh`       | single-line installation script |       | √   |     |
-| `install_local.sh` | local installation script       |       | √   |     |
-| `readthedocs.yml`  | readthedocs.io configuration    |       |     | √   |
-| `requirements.txt` | code requirements               |       | √   |     |
-| `setup.py`         | sphinx-based documentation      |       | √   |     |
+| file / directory   | description                     | urgent | C6  | C7  |
+|--------------------|---------------------------------|--------|-----|-----|
+| `csst_proto/`      | source code & data              | √√     | √   |     |
+| `doc/`             | sphinx-based documentation      |        |     | √   |
+| `example/`         | code examples                   | -      | -   | -   |
+| `tests/`           | unit tests                      |        |     | √   |
+| `.gitignore`       | git file                        |        | √   |     |
+| `.gitlab-ci.yml`   | gitlab CI/CD pipeline           |        |     | √   |
+| `LICENSE`          | code license                    |        | √   |     |
+| `README.md`        | readme file                     | √√     | √   |     |
+| `install.sh`       | single-line installation script |        | √   |     |
+| `install_local.sh` | local installation script       |        | √   |     |
+| `readthedocs.yml`  | readthedocs.io configuration    |        |     | √   |
+| `requirements.txt` | code requirements               | √      | √   |     |
+| `setup.py`         | sphinx-based documentation      | √√     | √   |     |