We expand on what sanitization means in the guidelines below instead
of making the steps more complicated.

service/dangerzone.md

@@ -25,12 +25,13 @@ you do?
  4. after a short delay, the file *disappears* (*gasp*! do not worry,
     they actually are moved to the `dangerzone-processing/` folder!)
 
- 5. then after another delay, if [Dangerzone][] succeeded, sanitized
-    appear in a `safe/` folder and the original files are moved into a
-    `dangerzone-processed/` folder
+ 5. then after another delay, the sanitized files appear in a `safe/`
+    folder and the original files are moved into a
+    `dangerzone/processed/` folder
 
- 6. if that didn't work, files end up in `dangerzone-rejected/` and no
-    new file appear in the `safe/` folder
+ 6. if that didn't work, the original files end up in
+    `dangerzone/rejected/` and no new file appear in the `safe/`
+    folder
 
 A few important guidelines:
 
@@ -38,6 +39,12 @@ A few important guidelines:
 
  * do **NOT** upload files **directly** in the `safe/` folder
 
+ * only the files in `safe/` are sanitized
+
+ * the files have been basically converted into harmless images, a bit
+   as if you had open the files on another computer, taken a
+   screenshot, and copied the files over back to your computer
+
  * some files cannot be processed by dangerzone, `.txt` files in
    particular, are known to end up in `dangerzone/rejected`