diff --git a/website/advanced/custom-language.md b/website/advanced/custom-language.md
index e69de29b..33b3926f 100644
--- a/website/advanced/custom-language.md
+++ b/website/advanced/custom-language.md
@@ -0,0 +1,3 @@
+# Custom Language Support
+
+This is experimental! See https://github.com/ast-grep/ast-grep.github.io/issues/98
diff --git a/website/advanced/match-algorithm.md b/website/advanced/match-algorithm.md
index e69de29b..11579f7f 100644
--- a/website/advanced/match-algorithm.md
+++ b/website/advanced/match-algorithm.md
@@ -0,0 +1,29 @@
+# Deep Dive in Pattern
+
+## What is TreeSitter
+
+## Core Concepts
+A list of ast-grep's concepts
+
+### Textual vs Structural
+TODO
+### AST vs CST
+TODO
+### Named nodes vs Unnamed nodes
+TODO
+### Kind vs Field
+TODO
+### Significant vs Trivial
+TODO
+
+## Match Algorithm
+
+In descending order of strict-ness
+
+* CST: all nodes are matched
+* Smart: all nodes except source trivial nodes are matched.
+* Significant: only significant nodes are matched
+* AST: only ast nodes are matched
+* Lenient: ast-nodes excluding comments are matched
+
+Currently ast-grep only supports cst.