diff --git a/src/libsyntax/ext/mtwt.rs b/src/libsyntax/ext/mtwt.rs
index 6f6eeb3debd..48895d34022 100644
--- a/src/libsyntax/ext/mtwt.rs
+++ b/src/libsyntax/ext/mtwt.rs
@@ -30,6 +30,7 @@ use std::collections::HashMap;
 // change the semantics--everything here is immutable--but
 // it should cut down on memory use *a lot*; applying a mark
 // to a tree containing 50 identifiers would otherwise generate
+// 50 new contexts
 pub struct SCTable {
     table: RefCell<Vec<SyntaxContext_>>,
     mark_memo: RefCell<HashMap<(SyntaxContext,Mrk),SyntaxContext>>,
@@ -160,7 +161,7 @@ fn with_resolve_table_mut<T>(op: |&mut ResolveTable| -> T) -> T {
 }
 
 // Resolve a syntax object to a name, per MTWT.
-// adding memoization to possibly resolve 500+ seconds in resolve for librustc (!)
+// adding memoization to resolve 500+ seconds in resolve for librustc (!)
 fn resolve_internal(id: Ident,
                     table: &SCTable,
                     resolve_table: &mut ResolveTable) -> Name {
diff --git a/src/libsyntax/parse/token.rs b/src/libsyntax/parse/token.rs
index 9549d5b8389..a93e8270d98 100644
--- a/src/libsyntax/parse/token.rs
+++ b/src/libsyntax/parse/token.rs
@@ -114,6 +114,7 @@ pub enum Nonterminal {
     NtPat( Gc<ast::Pat>),
     NtExpr(Gc<ast::Expr>),
     NtTy(  P<ast::Ty>),
+    // see IDENT, above, for meaning of bool in NtIdent:
     NtIdent(Box<ast::Ident>, bool),
     NtMeta(Gc<ast::MetaItem>), // stuff inside brackets for attributes
     NtPath(Box<ast::Path>),