diff --git a/doc/d-utils.md b/doc/d-utils.md
index a19975a..cc556bf 100644
--- a/doc/d-utils.md
+++ b/doc/d-utils.md
@@ -356,3 +356,16 @@ A simple module with less-common formatting functions.
 Converts given number to a string with two-digit fractional
 part. Should the fractional part be 0, it is replaced with the string
 "--".
+
+## util-tag [module]
+
+    (import util-tag)
+
+A unifying module for compound data structures tagging.
+
+### make-tag [syntax]
+
+* ```name``` - unquoted symbol to base the tag on
+
+Creates a unique and collision free symbol to identify compound data
+structures based on lists and pairs.
diff --git a/src/Makefile b/src/Makefile
index 7561dbf..c6a37e8 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -55,18 +55,20 @@ HACKERBASE-OBJS=hackerbase.o testing.o listing.o cal-month.o		\
 	 table-processor.o table-border.o table-style.o sgr-state.o	\
 	 util-utf8.o sgr-cell.o template-list-expander.o		\
 	 box-drawing.o util-list.o export-web-static.o util-dir.o	\
-	 dokuwiki.o racket-kwargs.o
+	 dokuwiki.o racket-kwargs.o duck.o
 
 GENDOC-SOURCES=gendoc.scm duck-extract.import.scm			\
 	util-time.import.scm util-csv.import.scm util-git.import.scm	\
 	util-io.import.scm util-stdout.import.scm			\
 	util-parser.import.scm util-list.import.scm			\
-	util-proc.import.scm util-format.import.scm
+	util-proc.import.scm util-format.import.scm			\
+	util-tag.import.scm
 
 GENDOC-OBJS=gendoc.o duck-extract.o util-time.o util-csv.o util-io.o	\
 	progress.o testing.o util-proc.o util-git.o util-io.o		\
 	util-stdout.o util-parser.o util-list.o util-proc.o		\
-	util-format.o
+	util-format.o racket-kwargs.o util-dict-list.o util-tag.o	\
+	util-set-list.o duck.o
 
 .PHONY: imports
 imports: $(HACKERBASE-DEPS)
@@ -276,7 +278,7 @@ UTIL-TIME-SOURCES=util-time.scm duck.import.scm
 util-time.o: util-time.import.scm
 util-time.import.scm: $(UTIL-TIME-SOURCES)
 
-UTIL-TAG-SOURCES=util-tag.scm testing.import.scm
+UTIL-TAG-SOURCES=util-tag.scm testing.import.scm duck.import.scm
 
 util-tag.o: util-tag.import.scm
 util-tag.import.scm: $(UTIL-TAG-SOURCES)
@@ -508,6 +510,7 @@ dokuwiki.import.scm: $(DOKUWIKI-SOURCES)
 DUCK-SOURCES=duck.scm
 
 duck.import.scm: $(DUCK-SOURCES)
+duck.o: duck.import.scm
 
 DUCK-EXTRACT-SOURCES=duck-extract.scm util-proc.import.scm
 
diff --git a/src/duck-extract.scm b/src/duck-extract.scm
index 1fc7a9f..efa6eae 100644
--- a/src/duck-extract.scm
+++ b/src/duck-extract.scm
@@ -169,6 +169,12 @@
    (newline)
    (print-duck-text (caddr sec)))
 
+ (define (print-duck-syntax sec)
+   (newline)
+   (print "### " (cadr sec) " [syntax]")
+   (newline)
+   (print-duck-text (caddr sec)))
+
  (define (print-duck-unknown sec)
    (print sec))
 
@@ -181,6 +187,7 @@
 	   ((VAR) (print-duck-variable (car mod)))
 	   ((PAR) (print-duck-parameter (car mod)))
 	   ((FUN) (print-duck-procedure (car mod)))
+	   ((STX) (print-duck-syntax (car mod)))
 	   (else (print-duck-unknown (car mod)))))
        (loop (cdr mod)))))
 
diff --git a/src/duck.scm b/src/duck.scm
index 154118a..780b1a2 100644
--- a/src/duck.scm
+++ b/src/duck.scm
@@ -22,6 +22,8 @@
 ;; CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 ;;
 
+(declare (unit duck))
+
 (module
  duck
  (
@@ -96,8 +98,8 @@
       (module
        modname
        exports
-       (import (only scheme define set! quote reverse list quasiquote)
-	       (only (chicken module) export)
+       (import scheme
+	       (chicken module)
 	       (chicken base)
 	       duck
 	       )
diff --git a/src/gendoc.scm b/src/gendoc.scm
index 6e6d02a..515e06d 100644
--- a/src/gendoc.scm
+++ b/src/gendoc.scm
@@ -28,4 +28,6 @@
 	  util-parser
 	  util-list
 	  util-proc
-	  util-format)
+	  util-format
+	  util-tag
+	  )
diff --git a/src/util-tag.scm b/src/util-tag.scm
index 53315df..ccf6ddb 100644
--- a/src/util-tag.scm
+++ b/src/util-tag.scm
@@ -25,8 +25,11 @@
 
 (declare (unit util-tag))
 
-(module
+(import duck)
+
+(module*
  util-tag
+ #:doc ("A unifying module for compound data structures tagging.")
  (
   make-tag
   util-tag-make
@@ -37,7 +40,11 @@
 	 (chicken random))
 
  ;; Syntactic wrapper to allow easy tag creation
- (define-syntax make-tag
+ (define-syntax/doc make-tag
+   ("* ```name``` - unquoted symbol to base the tag on
+
+Creates a unique and collision free symbol to identify compound data
+structures based on lists and pairs.")
    (syntax-rules ()
      ((_ tag)
       (util-tag-make 'tag))))