NEWS.md in lrama-0.6.2 vs NEWS.md in lrama-0.6.3

@@ -1,6 +1,40 @@
 # NEWS for Lrama
 
+## Lrama 0.6.3 (2024-02-15)
+
+### Bring Your Own Stack
+
+Provide functionalities for Bring Your Own Stack.
+
+Ruby’s Ripper library requires their own semantic value stack to manage Ruby Objects returned by user defined callback method. Currently Ripper uses semantic value stack (`yyvsa`) which is used by parser to manage Node. This hack introduces some limitation on Ripper. For example, Ripper can not execute semantic analysis depending on Node structure.
+
+Lrama introduces two features to support another semantic value stack by parser generator users.
+
+1. Callback entry points
+
+User can emulate semantic value stack by these callbacks.
+Lrama provides these five callbacks. Registered functions are called when each event happen. For example %after-shift function is called when shift happens on original semantic value stack.
+
+* `%after-shift` function_name
+* `%before-reduce` function_name
+* `%after-reduce` function_name
+* `%after-shift-error-token` function_name
+* `%after-pop-stack` function_name
+
+2. `$:n` variable to access index of each grammar symbols
+
+User also needs to access semantic value of their stack in grammar action. `$:n` provides the way to access to it. `$:n` is translated to the minus index from the top of the stack.
+For example
+
+```
+primary: k_if expr_value then compstmt if_tail k_end
+          {
+          /*% ripper: if!($:2, $:4, $:5) %*/
+          /* $:2 = -5, $:4 = -3, $:5 = -2. */
+          }
+```
+
 ## Lrama 0.6.2 (2024-01-27)
 
 ### %no-stdlib directive
 
 If `%no-stdlib` directive is set, Lrama doesn't load Lrama standard library for