diff --git a/libisofs/libisofs.h b/libisofs/libisofs.h
index 2d4f4f8..7b7747b 100644
--- a/libisofs/libisofs.h
+++ b/libisofs/libisofs.h
@@ -4067,20 +4067,22 @@ int iso_stream_update_size(IsoStream *stream);
 void iso_stream_get_id(IsoStream *stream, unsigned int *fs_id, dev_t *dev_id,
                       ino_t *ino_id);
 
-/* ts A90328 */
+/* ts A90406 */
 /**
- * Obtain the eventual input stream of a filter stream.
+ * Try to get eventual source path string of a stream. Meaning and availability
+ * of this string depends on the stream.class . Expect valid results with
+ * types "fsrc" and "cout".
  * @param stream
- *      The eventual filter stream to be inquired.
+ *     The stream to be inquired.
  * @param flag
- *      Bitfield for control purposes. Submit 0 for now.
+ *     Bitfield for control purposes, unused yet, submit 0
  * @return
- *      The input stream, if one exists. Elsewise NULL.
- *      No extra reference to the stream is taken by this call.
- * 
+ *     A copy of the path string. Apply free() when no longer needed.
+ *     NULL if no path string is available.
+ *
  * @since 0.6.18
- */    
-IsoStream *iso_stream_get_input_stream(IsoStream *stream, int flag);
+ */
+char *iso_stream_get_source_path(IsoStream *stream, int flag);
 
 
 /************ Error codes and return values for libisofs ********************/
@@ -4811,6 +4813,22 @@ int iso_file_add_external_filter(IsoFile *file, IsoExternalFilterCommand *cmd,
 int iso_file_remove_filter(IsoFile *file, int flag);
 
 
+/* ts A90328 */
+/**
+ * Obtain the eventual input stream of a filter stream.
+ * @param stream
+ *      The eventual filter stream to be inquired.
+ * @param flag
+ *      Bitfield for control purposes. Submit 0 for now.
+ * @return
+ *      The input stream, if one exists. Elsewise NULL.
+ *      No extra reference to the stream is taken by this call.
+ * 
+ * @since 0.6.18
+ */    
+IsoStream *iso_stream_get_input_stream(IsoStream *stream, int flag);
+
+
 /* ts A90402 */
 /**
  * Obtain the IsoExternalFilterCommand which is eventually associated with the
diff --git a/libisofs/stream.c b/libisofs/stream.c
index 8ecc56b..3ae17c1 100644
--- a/libisofs/stream.c
+++ b/libisofs/stream.c
@@ -14,6 +14,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <limits.h>
+#include <stdio.h>
 
 ino_t serial_id = (ino_t)1;
 ino_t mem_serial_id = (ino_t)1;
@@ -638,6 +639,8 @@ void iso_stream_get_file_name(IsoStream *stream, char *name)
         strcpy(name, "BOOT CATALOG");
     } else if (!strncmp(type, "mem ", 4)) {
         strcpy(name, "MEM SOURCE");
+    } else if (!strncmp(type, "extf", 4)) {
+        strcpy(name, "EXTERNAL FILTER");
     } else {
         strcpy(name, "UNKNOWN SOURCE");
     }
@@ -653,3 +656,34 @@ IsoStream *iso_stream_get_input_stream(IsoStream *stream, int flag)
     return class->get_input_stream(stream, 0);
 }
 
+/* ts A90406 API */
+char *iso_stream_get_source_path(IsoStream *stream, int flag)
+{
+    char *path = NULL, ivd[80], *raw_path = NULL;
+
+    if (stream == NULL) {
+        return NULL;
+    }
+    if (stream->class == &fsrc_stream_class) {
+        FSrcStreamData *fsrc_data = stream->data;
+
+        path = iso_file_source_get_path(fsrc_data->src);
+    } else if (stream->class == &cut_out_stream_class) {
+        struct cut_out_stream *cout_data = stream->data;
+
+        raw_path = iso_file_source_get_path(cout_data->src);
+        sprintf(ivd, " %.f %.f",
+                (double) cout_data->offset, (double) cout_data->size);
+        path= calloc(strlen(raw_path) + strlen(ivd) + 1, 1);
+        if (path == NULL) {
+            goto ex;
+        }
+        strcpy(path, raw_path);
+        strcat(path, ivd);
+    }
+ex:;
+    if (raw_path != NULL)
+        free(raw_path);
+    return path;
+}
+