diff --git a/docs/graphics/pbr.md b/docs/graphics/pbr.md
index 8f6f6edf9..03ae22552 100644
--- a/docs/graphics/pbr.md
+++ b/docs/graphics/pbr.md
@@ -9,7 +9,7 @@
   * $\mathbf h=\frac {w_i + w_o} {||w_i + w_o||}$ is the halfway vector (different from $\mathbf n$ !)
   * $m$ is the metalness
   * $\rho$ is the roughness
-  * $\mathbf a$ is the ambient color
+  * $\mathbf a$ is the ambient color (base color)
   * $s(\omega_i)$ is the occlusion probability from the shading point to light.
 * rendering Equation:
 
@@ -61,3 +61,20 @@ $$
 
   * direct term (from light): only dependent on the outgoing light direction.
   * indirect term (from other reflective surfaces): also dependent on the current shading point.
+
+
+### Metallic/Roughness v.s. Specular/Glossiness
+
+Except for the common metallic-roughness model, there is also specular-glossiness model for PBR (e.g., Unity).
+
+Both models can be converted between: https://kcoley.github.io/glTF/extensions/2.0/Khronos/KHR_materials_pbrSpecularGlossiness/examples/convert-between-workflows/
+
+$$
+\displaylines{
+glossiness = 1 - roughness \\
+diffuse = (1 - metallic) * basecolor \\ 
+specular = metallic * basecolor \\
+}
+$$
+
+A detailed documentation can be found: https://kcoley.github.io/glTF/extensions/2.0/Khronos/KHR_materials_pbrSpecularGlossiness/
diff --git a/docs/python/huggingface.md b/docs/python/huggingface.md
index fe39ec333..6e5f5eb29 100644
--- a/docs/python/huggingface.md
+++ b/docs/python/huggingface.md
@@ -10,9 +10,10 @@ pip install huggingface_hub
 huggingface-cli login
 ```
 
+
 ### upload models to a repo
 
-using python API:
+##### using python API:
 
 ```python
 from huggingface_hub import HfApi
@@ -36,22 +37,39 @@ api.upload_folder(
 )
 ```
 
-using CLI:
+##### using CLI:
+
+If the repo is not existing, it will be created automatically!
+
+```bash
+# upload local files to remote repo
+huggingface-cli upload <user/repo> <local path> <remote path>
+
+# upload everything to remote root dir
+huggingface-cli upload <user/repo> . .
 
-* Create the repo from website first.
+# upload a single file 
+huggingface-cli upload <user/repo> ./path/to/myfile # remote default to .
+huggingface-cli upload <user/repo> ./path/to/myfile /path/to/remote
 
-* upload by
+# upload multiple files: use  --include --exclude
+huggingface-cli upload <user/repo> --include="*.mp4" --exclude="unwanted*"
+```
+
+
+### download models
 
-  ```bash
-  huggingface-cli upload <user/repo> <local path> <remote path>
-  # example for uploading everything to remote root dir
-  huggingface-cli upload <user/repo> . .
-  ```
+##### using CLI:
 
-  
-### Downloads a repo
+By default these commands will download to `~/.cache/huggingface/hub`, use `--local-dir` to change it!
 
 ```bash
-huggingface-cli download <user/repo>
+# download single/multiple files to current dir
+huggingface-cli download <user/repo> <file1> [<file2> ...] --local-dir .
+
+huggingface-cli download stabilityai/stable-diffusion-xl-base-1.0 --include "*.safetensors" --exclude "*.fp16.*"*
+
+# download entire repo
+huggingface-cli download <user/repo> --local-dir .
 ```
 
diff --git a/docs/windows/powertoys.md b/docs/windows/powertoys.md
new file mode 100644
index 000000000..5534888cb
--- /dev/null
+++ b/docs/windows/powertoys.md
@@ -0,0 +1,18 @@
+## Power Toys
+
+Install from: https://github.com/microsoft/PowerToys/releases
+
+
+### Power Rename
+
+https://learn.microsoft.com/zh-cn/windows/powertoys/powerrename
+
+Examples:
+
+```bash
+# using regex
+(.*).mp4 --> $1_backup.mp4
+```
+
+MS use `$1` for group reference in regex, instead of `\1`!
+