long tag; /* tag, not used if no tagging */
unsigned long offset; /* Offset of this field in structure */
#ifndef NO_ASN1_FIELD_NAMES
-char *field_name; /* Field name */
+const char *field_name; /* Field name */
#endif
ASN1_ITEM_EXP *item; /* Relevant ASN1_ITEM or ASN1_ADB */
};