diff --git a/decode.rkt b/decode.rkt
index bd79554..4ee6f59 100644
--- a/decode.rkt
+++ b/decode.rkt
@@ -3,6 +3,7 @@
 (require "debug.rkt" "world.rkt")
 
 
+(define (symbols? x) (and (list? x) (andmap symbol? x)))
 
 (define+provide (to-string x)
   (if (string? x)
@@ -42,7 +43,7 @@
                       #:symbol-proc (symbol? . -> . xexpr?)
                       #:valid-char-proc (valid-char? . -> . xexpr?)
                       #:cdata-proc (cdata? . -> . xexpr?)
-                      #:exclude-tags (listof symbol?)  ) . ->* . txexpr?)
+                      #:exclude-tags symbols?) . ->* . txexpr?)
   
   
   (let loop ([x txexpr])
@@ -88,7 +89,7 @@
                       #:symbol-proc (symbol? . -> . xexpr?)
                       #:valid-char-proc (valid-char? . -> . xexpr?)
                       #:cdata-proc (cdata? . -> . xexpr?)
-                      #:exclude-tags (listof symbol?)  ) . ->* . txexpr-elements?)
+                      #:exclude-tags symbols?) . ->* . txexpr-elements?)
   
   (define temp-tag (gensym "temp-tag"))
   (define decode-result (decode `(temp-tag ,@elements)
diff --git a/file.rkt b/file.rkt
index b4d47e3..7022133 100644
--- a/file.rkt
+++ b/file.rkt
@@ -28,9 +28,11 @@
   (coerce/path? . -> . coerce/boolean?)
   (not ((->string path) . starts-with? . ".")))
 
+(define (paths? x) (and (list? x) (andmap path? x)))
+(define (complete-paths? x) (and (list? x) (andmap complete-path? x)))
 
 (define+provide/contract (visible-files dir)
-  (pathish? . -> . (listof path?))
+  (pathish? . -> . paths?)
   (filter visible? 
           (map (λ(p) (find-relative-path dir p)) 
                (filter file-exists? 
@@ -108,7 +110,7 @@
 
 
 (define+provide/contract (project-files-with-ext ext)
-  (coerce/symbol? . -> . (listof complete-path?))
+  (coerce/symbol? . -> . complete-paths?)
   (map ->complete-path (filter (λ(i) (has-ext? i ext)) (directory-list (world:current-project-root)))))
 
 
diff --git a/pagetree.rkt b/pagetree.rkt
index d5ca241..296d5d8 100644
--- a/pagetree.rkt
+++ b/pagetree.rkt
@@ -10,6 +10,9 @@
   (->boolean (and (symbol? x) (with-handlers ([exn:fail? (λ(e) #f)])
                                 (not (whitespace/nbsp? (->string x)))))))
 
+(define+provide (pagenodes? x)
+  (and (list? x) (andmap pagenode? x)))
+
 
 (define+provide (pagenodeish? x)
   (with-handlers ([exn:fail? (λ(e) #f)]) 
@@ -78,7 +81,7 @@
 
 
 (define+provide/contract (children p [pt (current-pagetree)])
-  (((or/c #f pagenodeish?)) (pagetree?) . ->* . (or/c #f (listof pagenode?)))  
+  (((or/c #f pagenodeish?)) (pagetree?) . ->* . (or/c #f pagenodes?))  
   (and pt p 
        (let ([pagenode (->pagenode p)])
          (if (equal? pagenode (car pt))
@@ -87,19 +90,18 @@
 
 
 (define+provide/contract (siblings pnish [pt (current-pagetree)])
-  (((or/c #f pagenodeish?)) (pagetree?) . ->* . (or/c #f (listof pagenode?)))  
+  (((or/c #f pagenodeish?)) (pagetree?) . ->* . (or/c #f pagenodes?))  
   (children (parent pnish pt) pt))
 
 
 ;; flatten tree to sequence
 (define+provide/contract (pagetree->list pt)
-  (pagetree? . -> . (listof pagenode?))
+  (pagetree? . -> . pagenodes?)
   ; use cdr to get rid of root tag at front
   (cdr (flatten pt))) 
 
 
 (define (adjacents side pnish [pt (current-pagetree)])
-  ; ((symbol? (or/c #f pagenodeish?)) (pagetree?) . ->* . (or/c #f (listof pagenode?)))
   (and pt pnish
        (let* ([pagenode (->pagenode pnish)]
               [proc (if (equal? side 'left) takef takef-right)]
@@ -108,12 +110,12 @@
 
 
 (define+provide/contract (previous* pnish [pt (current-pagetree)]) 
-  (((or/c #f pagenodeish?)) (pagetree?) . ->* . (or/c #f (listof pagenode?)))
+  (((or/c #f pagenodeish?)) (pagetree?) . ->* . (or/c #f pagenodes?))
   (adjacents 'left pnish pt))
 
 
 (define+provide/contract (next* pnish [pt (current-pagetree)]) 
-  (((or/c #f pagenodeish?)) (pagetree?) . ->* . (or/c #f (listof pagenode?)))
+  (((or/c #f pagenodeish?)) (pagetree?) . ->* . (or/c #f pagenodes?))
   (adjacents 'right pnish pt))
 
 
diff --git a/project.rkt b/project.rkt
index da85d17..9b381e0 100644
--- a/project.rkt
+++ b/project.rkt
@@ -1,9 +1,10 @@
 #lang racket/base
 (require "world.rkt" sugar/define sugar/coerce)
 
+(define (paths? x) (and (list? x) (andmap path? x)))
 
 (define/contract+provide (get-directory-require-files source-path) ; keep contract local to ensure coercion
-  (coerce/path? . -> . (or/c #f (listof path?)))
+  (coerce/path? . -> . (or/c #f paths?))
   (define possible-requires (list (simplify-path (build-path source-path 'up world:directory-require))))
   (and (andmap file-exists? possible-requires) possible-requires))
 
diff --git a/render.rkt b/render.rkt
index 5ea0aa4..a62ae61 100644
--- a/render.rkt
+++ b/render.rkt
@@ -16,8 +16,17 @@
 
 ;; using internal contracts to provide some extra safety (negligible performance hit)
 
+(define/contract (valid-path-arg? x)
+  (any/c . -> . boolean?)
+  (or (equal? #f x) (complete-path? x)))
+
+(define/contract (valid-path-args? x)
+  (any/c . -> . boolean?)
+  (and (list? x) (andmap valid-path-arg? x)))
+
+
 (define/contract (make-mod-dates-key paths)
-  ((listof (or/c #f complete-path?)) . -> . (listof (or/c #f complete-path?)))
+  (valid-path-args? . -> . valid-path-args?)
   paths) ; for now, this does nothing; maybe later, it will do more
 
 
@@ -27,20 +36,21 @@
 
 
 (define/contract (store-render-in-modification-dates . rest-paths)
-  (() #:rest (listof (or/c #f complete-path?)) . ->* . void?)
+  (() #:rest valid-path-args? . ->* . void?)
   (define key (make-mod-dates-key rest-paths))
   (hash-set! modification-date-hash key (map path->mod-date-value key)))
 
 
 (define/contract (modification-date-expired? . rest-paths)
-  (() #:rest (listof (or/c #f complete-path?)) . ->* . boolean?)
+  (() #:rest valid-path-args? . ->* . boolean?)
   (define key (make-mod-dates-key rest-paths))
   (or (not (key . in? . modification-date-hash))  ; no stored mod date
       (not (equal? (map path->mod-date-value key) (get modification-date-hash key))))) ; data has changed
 
+(define (list-of-pathish? x) (and (list? x) (andmap pathish? x)))
 
 (define/contract+provide (render-batch . xs)
-  (() #:rest (listof pathish?) . ->* . void?)
+  (() #:rest list-of-pathish? . ->* . void?)
   ;; Why not just (map render ...)?
   ;; Because certain files will pass through multiple times (e.g., templates)
   ;; And with render, they would be rendered repeatedly.
diff --git a/tag.rkt b/tag.rkt
index 17f9e6d..1a8abda 100644
--- a/tag.rkt
+++ b/tag.rkt
@@ -2,7 +2,7 @@
 (require txexpr sugar/define) 
 
 (define/contract+provide (make-default-tag-function . ids)
-  (() #:rest (listof txexpr-tag?) . ->* . procedure?)
+  (() #:rest txexpr-tags? . ->* . procedure?)
   (define (make-one-tag id)
     (λ x 
       (define reversed-pieces ; list of attribute pairs, and last element holds a list of everything else, then reversed
diff --git a/template.rkt b/template.rkt
index d709635..e1b25d6 100644
--- a/template.rkt
+++ b/template.rkt
@@ -24,7 +24,7 @@
 
 
 (define+provide/contract (select* key value-source)
-  (coerce/symbol? (or/c hash? txexpr? pagenode? pathish?) . -> . (or/c #f (listof txexpr-element?)))
+  (coerce/symbol? (or/c hash? txexpr? pagenode? pathish?) . -> . (or/c #f txexpr-elements?))
   (define metas-result (and (not (txexpr? value-source)) (select-from-metas key value-source)))
   (define doc-result (select-from-doc key value-source))
   (define result (append (or (and metas-result (list metas-result)) null) (or doc-result null)))
@@ -40,7 +40,7 @@
 
 
 (define+provide/contract (select-from-doc key doc-source)
-  (coerce/symbol? (or/c txexpr? pagenode? pathish?) . -> . (or/c #f (listof txexpr-element?)))
+  (coerce/symbol? (or/c txexpr? pagenode? pathish?) . -> . (or/c #f txexpr-elements?))
   (define doc (cond
                 [(txexpr? doc-source) doc-source]
                 [else (get-doc doc-source)]))