diff --git a/src/constr_SET.h b/src/constr_SET.h
new file mode 100644
index 0000000..0c78ed5
--- /dev/null
+++ b/src/constr_SET.h
@@ -0,0 +1,84 @@
+/*-
+ * Copyright (c) 2003, 2004 Lev Walkin <vlm@lionet.info>. All rights reserved.
+ * Redistribution and modifications are permitted subject to BSD license.
+ */
+#ifndef	_CONSTR_SET_H_
+#define	_CONSTR_SET_H_
+
+#include <asn_application.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+typedef struct asn_SET_specifics_s {
+	/*
+	 * Target structure description.
+	 */
+	int struct_size;	/* Size of the target structure. */
+	int ctx_offset;		/* Offset of the asn_struct_ctx_t member */
+	int pres_offset;	/* Offset of _presence_map member */
+
+	/*
+	 * Tags to members mapping table (sorted).
+	 * Sometimes suitable for DER encoding (untagged CHOICE is present);
+	 * if so, tag2el_count will be greater than td->elements_count.
+	 */
+	asn_TYPE_tag2member_t *tag2el;
+	int tag2el_count;
+
+	/*
+	 * Tags to members mapping table, second edition.
+	 * Suitable for CANONICAL-XER encoding.
+	 */
+	asn_TYPE_tag2member_t *tag2el_cxer;
+	int tag2el_cxer_count;
+
+	/*
+	 * Extensions-related stuff.
+	 */
+	int extensible;				/* Whether SET is extensible */
+	unsigned int *_mandatory_elements;	/* Bitmask of mandatory ones */
+} asn_SET_specifics_t;
+
+/*
+ * A set specialized functions dealing with the SET type.
+ */
+asn_struct_free_f SET_free;
+asn_struct_print_f SET_print;
+asn_constr_check_f SET_constraint;
+ber_type_decoder_f SET_decode_ber;
+der_type_encoder_f SET_encode_der;
+xer_type_decoder_f SET_decode_xer;
+xer_type_encoder_f SET_encode_xer;
+per_type_decoder_f SET_decode_uper;
+per_type_encoder_f SET_encode_uper;
+
+/***********************
+ * Some handy helpers. *
+ ***********************/
+
+/*
+ * Figure out whether the SET member indicated by PR_x has already been decoded.
+ * It is very simple bitfield test, despite its visual complexity.
+ */
+#define	ASN_SET_ISPRESENT(set_ptr, PR_x)				\
+	ASN_SET_ISPRESENT2(&((set_ptr)->_presence_map), PR_x)
+#define	ASN_SET_ISPRESENT2(map_ptr, PR_x)				\
+	(((unsigned int *)(map_ptr))					\
+		[(PR_x)	/ (8 * sizeof(unsigned int))]			\
+		& (1 << ((8 * sizeof(unsigned int)) - 1			\
+		- ((PR_x) % (8 * sizeof(unsigned int))))))
+
+#define	ASN_SET_MKPRESENT(map_ptr, PR_x)				\
+	(((unsigned int *)(map_ptr))					\
+		[(PR_x)	/ (8 * sizeof(unsigned int))]			\
+		|= (1 << ((8 * sizeof(unsigned int)) - 1		\
+		- ((PR_x) % (8 * sizeof(unsigned int))))))
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* _CONSTR_SET_H_ */