diff --git a/genkicat/tree.c b/genkicat/tree.c
index 200a044..6b5da60 100644
--- a/genkicat/tree.c
+++ b/genkicat/tree.c
@@ -23,6 +23,9 @@
 struct node *tree = NULL;
 
 
+/* ----- Tree parsing ------------------------------------------------------ */
+
+
 void read_tree(FILE *file)
 {
 	char buf[1100]; /* more than enough */
@@ -56,7 +59,7 @@ next:
 			if (*p != ' ' && *p != '\t')
 				e = p;
 		if (!last && n) {
-			fprintf(stderr, "first entry must not be intended\n");
+			fprintf(stderr, "first entry must not be indented\n");
 			exit(1);
 		}
 		name = malloc(e-s+2);
@@ -94,6 +97,9 @@ next:
 }
 
 
+/* ----- Description parsing ----------------------------------------------- */
+
+
 static struct node *find_comp(struct node *node, const char *name)
 {
 	struct node *found;
@@ -206,6 +212,9 @@ void read_desc(FILE *file)
 }
 
 
+/* ----- Associate library entries with tree nodes ------------------------- */
+
+
 void set_libs(const struct lib *lib, struct node *node)
 {
 	while (node) {
@@ -223,6 +232,9 @@ void set_libs(const struct lib *lib, struct node *node)
 }
 
 
+/* ----- Debug dumps ------------------------------------------------------- */
+
+
 static void dump_tree_level(const struct node *tree, int level)
 {
 	const struct node *n;