diff --git a/ReadingSystems/Kindle/KF8/readme.md b/ReadingSystems/Kindle/KF8/readme.md
index dcd27bb..73cd204 100644
--- a/ReadingSystems/Kindle/KF8/readme.md
+++ b/ReadingSystems/Kindle/KF8/readme.md
@@ -1,8 +1,20 @@
 # KF8
 
-Easy one. We’ve got some kind of “ePub 2.5” format there, with very few alterations and undocumented support of `-webkit-` prefixed properties as a bonus.
+Easy one. It feels like we’ve got some kind of “ePub 2.5” format there, with few alterations and undocumented support of `-webkit-` prefixed properties as a bonus.
 
-Now, there is one important thing which is worth reporting…
+Actually, things are a bit more complicated. 
+
+KF8 can be considered the foundation for KFX; it works the same at the fundamental level.
+
+Here is what happens: 
+
+1. contents are cut into fragments (with the corresponding attributes, styles, etc.);
+2. the renderer is just an HTML skeleton;
+3. fragments are then re-injected into this skeleton at runtime.
+
+If you unpack a Kindle Mobi file using Kindle/Mobi Unpack, the app is actually rebuilding the EPUB file bu re-injecting those fragments into the skeleton.
+
+Now, there is another important thing which is worth reporting…
 
 **If part of a CSS declaration (prop OR value) is not supported, the whole is erased.**