diff --git a/include/haproxy/hlua-t.h b/include/haproxy/hlua-t.h
index 9716868f8..ac0b7d541 100644
--- a/include/haproxy/hlua-t.h
+++ b/include/haproxy/hlua-t.h
@@ -255,6 +255,7 @@ struct hlua_patref_iterator_context {
 	struct hlua_patref *ref;
 	struct bref bref;       /* back-reference from the pat_ref_elt being accessed
 	                         * during listing */
+	struct pat_ref_gen *gen; /* the generation we are iterating over */
 };
 
 #else /* USE_LUA */
diff --git a/include/haproxy/pattern-t.h b/include/haproxy/pattern-t.h
index a78c98443..42da6ed33 100644
--- a/include/haproxy/pattern-t.h
+++ b/include/haproxy/pattern-t.h
@@ -107,6 +107,7 @@ struct pat_ref {
 	struct list list; /* Used to chain refs. */
 	char *reference; /* The reference name. */
 	char *display; /* String displayed to identify the pattern origin. */
+	struct ceb_root *gen_root; /* The tree mapping generation IDs to pattern reference elements */
 	struct list head; /* The head of the list of struct pat_ref_elt. */
 	struct ceb_root *ceb_root; /* The tree where pattern reference elements are attached. */
 	struct list pat; /* The head of the list of struct pattern_expr. */
@@ -121,6 +122,16 @@ struct pat_ref {
 	event_hdl_sub_list e_subs;       /* event_hdl: pat_ref's subscribers list (atomically updated) */
 };
 
+/* This struct represents all the elements in a pattern reference generation. The tree
+ * is used most of the time, but we also maintain a list for when order matters.
+ */
+struct pat_ref_gen {
+	struct list head; /* The head of the list of struct pat_ref_elt. */
+	struct ceb_root *elt_root; /* The tree where pattern reference elements are attached. */
+	struct ceb_node gen_node; /* Linkage for the gen_root cebtree in struct pat_ref */
+	unsigned int gen_id;
+};
+
 /* This is a part of struct pat_ref. Each entry contains one pattern and one
  * associated value as original string. All derivative forms (via exprs) are
  * accessed from list_head or tree_head. Be careful, it's variable-sized!
diff --git a/include/haproxy/pattern.h b/include/haproxy/pattern.h
index 1f3fdf164..73245096b 100644
--- a/include/haproxy/pattern.h
+++ b/include/haproxy/pattern.h
@@ -191,6 +191,8 @@ struct pat_ref_elt *pat_ref_find_elt(struct pat_ref *ref, const char *key);
 struct pat_ref_elt *pat_ref_gen_find_elt(struct pat_ref *ref, unsigned int gen_id, const char *key);
 struct pat_ref_elt *pat_ref_append(struct pat_ref *ref, const char *pattern, const char *sample, int line);
 struct pat_ref_elt *pat_ref_load(struct pat_ref *ref, unsigned int gen, const char *pattern, const char *sample, int line, char **err);
+struct pat_ref_gen *pat_ref_gen_new(struct pat_ref *ref, unsigned int gen_id);
+struct pat_ref_gen *pat_ref_gen_get(struct pat_ref *ref, unsigned int gen_id);
 int pat_ref_push(struct pat_ref_elt *elt, struct pattern_expr *expr, int patflags, char **err);
 int pat_ref_add(struct pat_ref *ref, const char *pattern, const char *sample, char **err);
 int pat_ref_set(struct pat_ref *ref, const char *pattern, const char *sample, char **err);
diff --git a/src/map.c b/src/map.c
index 7a6bd36f6..b02224d8d 100644
--- a/src/map.c
+++ b/src/map.c
@@ -362,6 +362,7 @@ struct show_map_ctx {
 	unsigned int display_flags;
 	unsigned int curr_gen;  /* current/latest generation, for show/clear */
 	unsigned int prev_gen;  /* prev generation, for clear */
+	struct pat_ref_gen *gen; /* link to the generation being displayed, for show */
 	enum {
 		STATE_INIT = 0, /* initialize list and backrefs */
 		STATE_LIST,     /* list entries */
diff --git a/src/pattern.c b/src/pattern.c
index 0c662a989..8270d3640 100644
--- a/src/pattern.c
+++ b/src/pattern.c
@@ -15,6 +15,7 @@
 #include <errno.h>
 
 #include <import/cebs_tree.h>
+#include <import/ceb32_tree.h>
 #include <import/ebistree.h>
 #include <import/ebpttree.h>
 #include <import/ebsttree.h>
@@ -31,6 +32,18 @@
 #include <haproxy/xxhash.h>
 
 
+/* Convenience macros for iterating over generations. */
+#define pat_ref_gen_foreach(gen, ref)								\
+	for (gen = cebu32_item_first(&ref->gen_root, gen_node, gen_id, struct pat_ref_gen);	\
+	     gen;										\
+	     gen = cebu32_item_next(&ref->gen_root, gen_node, gen_id, gen))
+
+/* Safe variant that allows deleting an entry in the body of the loop. */
+#define pat_ref_gen_foreach_safe(gen, next, ref)						\
+	for (gen = cebu32_item_first(&ref->gen_root, gen_node, gen_id, struct pat_ref_gen);	\
+	     gen && (next = cebu32_item_next(&ref->gen_root, gen_node, gen_id, gen), 1);	\
+	     gen = next)
+
 const char *const pat_match_names[PAT_MATCH_NUM] = {
 	[PAT_MATCH_FOUND] = "found",
 	[PAT_MATCH_BOOL]  = "bool",
@@ -1621,6 +1634,37 @@ int pat_ref_delete_by_id(struct pat_ref *ref, struct pat_ref_elt *refelt)
 	return 0;
 }
 
+/* Create a new generation object.
+ *
+ * Returns NULL in case of memory allocation failure.
+ */
+struct pat_ref_gen *pat_ref_gen_new(struct pat_ref *ref, unsigned int gen_id)
+{
+	struct pat_ref_gen *gen, *old;
+
+	gen = calloc(1, sizeof(struct pat_ref_gen));
+	if (!gen)
+		return NULL;
+
+	LIST_INIT(&gen->head);
+	ceb_init_root(&gen->elt_root);
+	gen->gen_id = gen_id;
+
+	old = cebu32_item_insert(&ref->gen_root, gen_node, gen_id, gen);
+	BUG_ON(old != gen, "Generation ID already exists");
+
+	return gen;
+}
+
+/* Find the generation <gen_id> in the pattern reference <ref>.
+ *
+ * Returns NULL if the generation cannot be found.
+ */
+struct pat_ref_gen *pat_ref_gen_get(struct pat_ref *ref, unsigned int gen_id)
+{
+	return cebu32_item_lookup(&ref->gen_root, gen_node, gen_id, gen_id, struct pat_ref_gen);
+}
+
 /* This function removes all elements belonging to <gen_id> and matching <key>
  * from the reference <ref>.
  * This function returns 1 if the deletion is done and returns 0 if