diff --git a/src/export/traverse.rs b/src/export/traverse.rs
index a44398c..bb25a7a 100644
--- a/src/export/traverse.rs
+++ b/src/export/traverse.rs
@@ -143,7 +143,7 @@ pub trait Traverser {
 
             BLOCK_CONTENT | LIST_ITEM_CONTENT => traverse_children!(node),
 
-            _ => {}
+            kind => debug_assert!(!kind.is_element() && !kind.is_object()),
         }
     }
 
diff --git a/src/syntax/block.rs b/src/syntax/block.rs
index cabc90b..6e142ec 100644
--- a/src/syntax/block.rs
+++ b/src/syntax/block.rs
@@ -20,16 +20,15 @@ fn block_node_base(input: Input) -> IResult<Input, GreenElement, ()> {
     let (input, (block_begin, name)) = block_begin_node(input)?;
     let (input, pre_blank) = blank_lines(input)?;
 
-    let (kind, is_greater_block) = match name {
-        s if s.eq_ignore_ascii_case("COMMENT") => (COMMENT_BLOCK, false),
-        s if s.eq_ignore_ascii_case("EXAMPLE") => (EXAMPLE_BLOCK, false),
-        s if s.eq_ignore_ascii_case("EXPORT") => (EXPORT_BLOCK, false),
-        s if s.eq_ignore_ascii_case("SRC") => (SOURCE_BLOCK, false),
-
-        s if s.eq_ignore_ascii_case("CENTER") => (CENTER_BLOCK, true),
-        s if s.eq_ignore_ascii_case("QUOTE") => (QUOTE_BLOCK, true),
-        s if s.eq_ignore_ascii_case("VERSE") => (VERSE_BLOCK, true),
-        _ => (SPECIAL_BLOCK, true),
+    let kind = match name {
+        s if s.eq_ignore_ascii_case("COMMENT") => COMMENT_BLOCK,
+        s if s.eq_ignore_ascii_case("EXAMPLE") => EXAMPLE_BLOCK,
+        s if s.eq_ignore_ascii_case("EXPORT") => EXPORT_BLOCK,
+        s if s.eq_ignore_ascii_case("SRC") => SOURCE_BLOCK,
+        s if s.eq_ignore_ascii_case("CENTER") => CENTER_BLOCK,
+        s if s.eq_ignore_ascii_case("QUOTE") => QUOTE_BLOCK,
+        s if s.eq_ignore_ascii_case("VERSE") => VERSE_BLOCK,
+        _ => SPECIAL_BLOCK,
     };
 
     for (input, contents) in line_starts_iter(input.as_str()).map(|i| input.take_split(i)) {
@@ -38,7 +37,7 @@ fn block_node_base(input: Input) -> IResult<Input, GreenElement, ()> {
 
             let mut children = vec![block_begin];
             children.extend(pre_blank);
-            if is_greater_block {
+            if kind.is_greater_element() {
                 children.push(node(BLOCK_CONTENT, element_nodes(contents)?));
             } else {
                 children.push(node(BLOCK_CONTENT, comma_quoted_text_nodes(contents)));
diff --git a/src/syntax/mod.rs b/src/syntax/mod.rs
index b16bb75..a77423f 100644
--- a/src/syntax/mod.rs
+++ b/src/syntax/mod.rs
@@ -222,3 +222,81 @@ impl From<SyntaxKind> for rowan::SyntaxKind {
         OrgLanguage::kind_to_raw(value)
     }
 }
+
+impl SyntaxKind {
+    /// whether this node is [object](https://orgmode.org/worg/org-syntax.html#Objects)
+    pub fn is_object(&self) -> bool {
+        matches!(
+            self,
+            SyntaxKind::ENTITY
+                | SyntaxKind::LATEX_FRAGMENT
+                | SyntaxKind::SNIPPET
+                | SyntaxKind::FN_REF
+                | SyntaxKind::INLINE_CALL
+                | SyntaxKind::INLINE_SRC
+                | SyntaxKind::LINK
+                | SyntaxKind::MACROS
+                | SyntaxKind::RADIO_TARGET
+                | SyntaxKind::COOKIE
+                | SyntaxKind::ORG_TABLE_CELL
+                | SyntaxKind::TIMESTAMP_ACTIVE
+                | SyntaxKind::TIMESTAMP_INACTIVE
+                | SyntaxKind::TIMESTAMP_DIARY
+                | SyntaxKind::BOLD
+                | SyntaxKind::ITALIC
+                | SyntaxKind::UNDERLINE
+                | SyntaxKind::VERBATIM
+                | SyntaxKind::CODE
+                | SyntaxKind::STRIKE
+        )
+    }
+
+    /// whether this node is [element](https://orgmode.org/worg/org-syntax.html#Elements)
+    pub fn is_element(&self) -> bool {
+        matches!(self, SyntaxKind::HEADLINE | SyntaxKind::SECTION)
+            || self.is_lesser_element()
+            || self.is_greater_element()
+    }
+
+    /// whether this node is [lesser element](https://orgmode.org/worg/org-syntax.html#Lesser_Elements)
+    pub fn is_lesser_element(&self) -> bool {
+        matches!(
+            self,
+            SyntaxKind::COMMENT_BLOCK
+                | SyntaxKind::EXAMPLE_BLOCK
+                | SyntaxKind::EXPORT_BLOCK
+                | SyntaxKind::SOURCE_BLOCK
+                | SyntaxKind::VERSE_BLOCK
+                | SyntaxKind::CLOCK
+                | SyntaxKind::PLANNING
+                | SyntaxKind::COMMENT
+                | SyntaxKind::FIXED_WIDTH
+                | SyntaxKind::RULE
+                | SyntaxKind::KEYWORD
+                | SyntaxKind::AFFILIATED_KEYWORD
+                | SyntaxKind::BABEL_CALL
+                | SyntaxKind::LATEX_ENVIRONMENT
+                | SyntaxKind::NODE_PROPERTY
+                | SyntaxKind::PARAGRAPH
+                | SyntaxKind::ORG_TABLE_RULE_ROW
+                | SyntaxKind::ORG_TABLE_STANDARD_ROW
+        )
+    }
+
+    /// whether this node is [greater element](https://orgmode.org/worg/org-syntax.html#Greater_Elements)
+    pub fn is_greater_element(&self) -> bool {
+        matches!(
+            self,
+            SyntaxKind::CENTER_BLOCK
+                | SyntaxKind::QUOTE_BLOCK
+                | SyntaxKind::SPECIAL_BLOCK
+                | SyntaxKind::DRAWER
+                | SyntaxKind::DYN_BLOCK
+                | SyntaxKind::FN_DEF
+                | SyntaxKind::LIST_ITEM
+                | SyntaxKind::LIST
+                | SyntaxKind::PROPERTY_DRAWER
+                | SyntaxKind::ORG_TABLE
+        )
+    }
+}