Use quotes instead of backticks in user-facing messages.

Suggested by Benno Schulenberg <coordinator@translationproject.org>.

* doc/modules/skribilo/documentation/api.scm,
  src/guile/skribilo.scm, src/guile/skribilo/condition.scm,
  src/guile/skribilo/engine/lout.scm,
  src/guile/skribilo/package/base.scm,
  src/guile/skribilo/package/jfp.scm,
  src/guile/skribilo/package/lncs.scm,
  src/guile/skribilo/package/pie.scm,
  src/guile/skribilo/package/slide/latex.scm,
  src/guile/skribilo/utils/compat.scm,
  src/guile/skribilo/ast.scm,
  src/guile/skribilo/biblio.scm,
  src/guile/skribilo/engine/html.scm,
  src/guile/skribilo/engine/info.scm,
  src/guile/skribilo/index.scm,
  src/guile/skribilo/package/web-book2.scm,
  src/guile/skribilo/reader/rss-2.scm,
  src/guile/skribilo/source.scm,
  src/guile/skribilo/utils/compat.scm,
  src/guile/skribilo/verify.scm: Change `foo' to 'foo'.

19 files changed, 60 insertions, 59 deletions

diff --git a/doc/modules/skribilo/documentation/api.scm b/doc/modules/skribilo/documentation/api.scm
index 36ba0e7..620b3d1 100644
--- a/doc/modules/skribilo/documentation/api.scm
+++ b/doc/modules/skribilo/documentation/api.scm
@@ -271,7 +271,7 @@ def @SkribiloExample named @Title {} right x {
 		    %skribilo-module-reader)))
       (if (not (string? f))
 	  (skribe-error 'api-search-definition
-			(format #f "can't find source file `~a' in path"
+			(format #f "can't find source file '~a' in path"
 				file)
 			path)
 	  (with-input-from-file f
@@ -281,7 +281,7 @@ def @SkribiloExample named @Title {} right x {
 		   (if (eof-object? exp)
 		       (skribe-error 'api-search-definition
 				     (format #f
-					     "can't find `~a' definition" id)
+					     "can't find '~a' definition" id)
 				     file)
 		       (or (pred id exp) (loop (read))))))))))
 
@@ -379,7 +379,7 @@ def @SkribiloExample named @Title {} right x {
        '())
       (else
        (skribe-error 'define-markup-formals
-		     "Illegal `define-markup' form"
+		     "Illegal 'define-markup' form"
 		     def))))
 
 ;*---------------------------------------------------------------------*/
@@ -402,7 +402,7 @@ def @SkribiloExample named @Title {} right x {
        '((ident #f) (class #f)))
       (else
        (skribe-error 'define-markup-options
-		     "Illegal `define-markup' form"
+		     "Illegal 'define-markup' form"
 		     def))))
 
 ;*---------------------------------------------------------------------*/
@@ -423,7 +423,7 @@ def @SkribiloExample named @Title {} right x {
 			 (if (or (not (pair? (cdr rest)))
 				 (not (symbol? (cadr rest))))
 			     (skribe-error 'define-markup-rest
-					   "Illegal `define-markup' form"
+					   "Illegal 'define-markup' form"
 					   def)
 			     (cadr rest))
 			 #f))))))
@@ -433,7 +433,7 @@ def @SkribiloExample named @Title {} right x {
        'node)
       (else
        (skribe-error 'define-markup-rest
-		     "Illegal `define-markup' form"
+		     "Illegal 'define-markup' form"
 		     def))))
 
 ;*---------------------------------------------------------------------*/
@@ -826,7 +826,7 @@ def @SkribiloExample named @Title {} right x {
           (resolve (lambda (n e env)
                      (cond
                       ((engine-format? "latex" e)
-                       (skribe-warning 3 "`doc-engine' not rendered in LaTeX")
+                       (skribe-warning 3 "'doc-engine' not rendered in LaTeX")
                        #f)
                       ((engine-format? "lout" e)
                        (list (map (lambda (c)
diff --git a/src/guile/skribilo.scm b/src/guile/skribilo.scm
index 33c08fb..463be51 100644
--- a/src/guile/skribilo.scm
+++ b/src/guile/skribilo.scm
@@ -1,6 +1,7 @@
 ;;; skribilo.scm  --  The Skribilo document processor.
 ;;;
-;;; Copyright 2005, 2006, 2007, 2008, 2009, 2011, 2012, 2013  Ludovic Courtès <ludo@gnu.org>
+;;; Copyright 2005, 2006, 2007, 2008, 2009, 2011, 2012, 2013,
+;;;   2015  Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright 2003, 2004  Erick Gallesio - I3S-CNRS/ESSI <eg@unice.fr>
 ;;;
 ;;;
@@ -67,16 +68,16 @@ Process Skribilo document from file INPUT (or the standard input) using the
 specified reader syntax, and produce its output using the specified engine.
 "))
   (display (_ "
-  -R, --reader=READER    Use READER to parse the input file, e.g., `skribe'
-                         (default) or `outline'."))
+  -R, --reader=READER    Use READER to parse the input file, e.g., 'skribe'
+                         (default) or 'outline'."))
   (display (_ "
-  -t, --target=ENGINE    Use ENGINE as the output engine, e.g., `html'."))
+  -t, --target=ENGINE    Use ENGINE as the output engine, e.g., 'html'."))
   (display (_ "
   -c, --custom=C=VAL     Use VAL as the value of ENGINE's custom C."))
   (display (_ "
   -o, --output=FILE      Write output to FILE."))
   (display (_ "
-      --compat=COMPAT    Use COMPAT as the compatibility layer, e.g., `skribe'."))
+      --compat=COMPAT    Use COMPAT as the compatibility layer, e.g., 'skribe'."))
   (newline)
   (display (_ "
   -I, --doc-path=DIR     Prepend DIR to the document include path."))
@@ -90,7 +91,7 @@ specified reader syntax, and produce its output using the specified engine.
   -U, --sui-path=DIR     Prepend DIR to the Skribe URL Index (SUI) search path."))
   (newline)
   (display (_ "
-  -b, --base=BASE        Strip BASE from all hyperlinks (`html' engine)."))
+  -b, --base=BASE        Strip BASE from all hyperlinks ('html' engine)."))
   (display (_ "
   -e, --eval=EXPR        Prepend EXPR to the list of expressions to be
                          evaluted before the input file is processed."))
diff --git a/src/guile/skribilo/ast.scm b/src/guile/skribilo/ast.scm
index 1b0b47b..853d14d 100644
--- a/src/guile/skribilo/ast.scm
+++ b/src/guile/skribilo/ast.scm
@@ -151,7 +151,7 @@
 	       (option (markup-unknown-option-error:option c)))
            (show-location markup)
 	   (format (current-error-port)
-		   (_ "~a: unknown markup option for `~a'~%")
+		   (_ "~a: unknown markup option for '~a'~%")
 		   option markup)))
 
 	((markup-already-bound-error? c)
@@ -159,7 +159,7 @@
 	       (ident  (markup-already-bound-error:ident  c)))
            (show-location markup)
 	   (format (current-error-port)
-		   (_ "`~a' (~a): markup identifier already bound~%")
+		   (_ "'~a' (~a): markup identifier already bound~%")
 		   ident
 		   (if (markup? markup)
 		       (markup-markup markup)
@@ -493,7 +493,7 @@
   (let ((ident (if (null? ident) (markup-ident node) (car ident))))
     (if ident
 	(let ((handle (hash-get-handle (document-node-table doc) ident)))
-	  ;;(format (current-error-port) "binding `~a' in `~a'~%" ident node)
+	  ;;(format (current-error-port) "binding '~a' in '~a'~%" ident node)
 	  (if (and (pair? handle) (not (eq? (cdr handle) node)))
 	      (raise (condition (&markup-already-bound-error
 				 (ident  ident)
diff --git a/src/guile/skribilo/biblio.scm b/src/guile/skribilo/biblio.scm
index 455f58e..b168d8a 100644
--- a/src/guile/skribilo/biblio.scm
+++ b/src/guile/skribilo/biblio.scm
@@ -115,12 +115,12 @@
                        entry))))
 	((biblio-template-error? c)
 	 (format (current-error-port)
-                 (_ "invalid bibliography entry template: `~a', in `~a'~%")
+                 (_ "invalid bibliography entry template: '~a', in '~a'~%")
                  (biblio-template-error:expression c)
                  (biblio-template-error:template c)))
         ((biblio-parse-error? c)
          (format (current-error-port)
-                 (_ "invalid bibliography entry s-exp: `~a'~%")
+                 (_ "invalid bibliography entry s-exp: '~a'~%")
                  (biblio-parse-error:sexp c)))
 	(else
 	 (format (current-error-port)
@@ -183,10 +183,10 @@
 		    'bib
 		    (format #f "duplicated bibliographic entry ~a'.\n" ident)
 		    (if ofrom
-			(format #f " using version of `~a'.\n" ofrom)
+			(format #f " using version of '~a'.\n" ofrom)
 			"")
 		    (if from
-			(format #f " ignoring version of `~a'." from)
+			(format #f " ignoring version of '~a'." from)
 			" ignoring redefinition."))))
 
 
diff --git a/src/guile/skribilo/condition.scm b/src/guile/skribilo/condition.scm
index 0b86b76..280f547 100644
--- a/src/guile/skribilo/condition.scm
+++ b/src/guile/skribilo/condition.scm
@@ -129,7 +129,7 @@
           (display-backtrace stack (current-error-port)))
         (begin
           (format (current-error-port) (_ "Call stack trace not available.~%"))
-          (format (current-error-port) (_ "Use `GUILE=\"guile --debug\" skribilo ...' for a detailed stack trace.~%"))))))
+          (format (current-error-port) (_ "Use 'GUILE=\"guile --debug\" skribilo ...' for a detailed stack trace.~%"))))))
 
 (define (abort exit-val)
   ;; Abort the `skribilo' command-line program, returning EXIT-VAL.
@@ -147,21 +147,21 @@
    (lambda (c)
      (cond  ((invalid-argument-error? c)
 	     (format (current-error-port)
-                     (_ "in `~a': invalid argument: ~S~%")
+                     (_ "in '~a': invalid argument: ~S~%")
 		     (invalid-argument-error:proc-name c)
 		     (invalid-argument-error:argument c))
 	     (abort exit-val))
 
 	    ((too-few-arguments-error? c)
 	     (format (current-error-port)
-                     (_ "in `~a': too few arguments: ~S~%")
+                     (_ "in '~a': too few arguments: ~S~%")
 		     (too-few-arguments-error:proc-name c)
 		     (too-few-arguments-error:arguments c))
              (abort exit-val))
 
 	    ((file-search-error? c)
 	     (format (current-error-port)
-                     (_ "~a: not found in path `~S'~%")
+                     (_ "~a: not found in path '~S'~%")
 		     (file-error:file-name c)
 		     (file-search-error:path c))
 	     (abort exit-val))
diff --git a/src/guile/skribilo/engine/html.scm b/src/guile/skribilo/engine/html.scm
index 12c068e..3b06ae1 100644
--- a/src/guile/skribilo/engine/html.scm
+++ b/src/guile/skribilo/engine/html.scm
@@ -728,7 +728,7 @@
 	  (id (markup-ident n)))
       (unless (string? id)
 	 (skribe-error '&html-generic-header
-		       (format #f "Illegal identifier `~a'" id)
+		       (format #f "Illegal identifier '~a'" id)
 		       n))
       ;; title
       (output (new markup
@@ -1094,7 +1094,7 @@
 			(f (html-file c e)))
 		    (unless (string? id)
 		       (skribe-error 'toc
-				     (format #f "illegal identifier `~a'" id)
+				     (format #f "illegal identifier '~a'" id)
 				     c))
 		    (display " <tr>")
 		    ;; blank columns
diff --git a/src/guile/skribilo/engine/info.scm b/src/guile/skribilo/engine/info.scm
index d92e47f..7cf2fad 100644
--- a/src/guile/skribilo/engine/info.scm
+++ b/src/guile/skribilo/engine/info.scm
@@ -174,7 +174,7 @@
                   (begin
                     (skribe-warning/ast 1 section
                                         (format #f
-                                                (_ "Info node title `~A' already used")
+                                                (_ "Info node title '~A' already used")
                                                 title))
                     (skribe-warning/ast 1 (cdr same-named)
                                         (_ "previous occurrence was here"))
diff --git a/src/guile/skribilo/engine/lout.scm b/src/guile/skribilo/engine/lout.scm
index 1a3467c..cf5bd46 100644
--- a/src/guile/skribilo/engine/lout.scm
+++ b/src/guile/skribilo/engine/lout.scm
@@ -418,12 +418,12 @@
 	     "    @PageMark @Tag\n"
 	     "}\n\n"
 
-	     "# @SkribiloLeaders is used in `toc'\n"
+	     "# @SkribiloLeaders is used in 'toc'\n"
 	     "# (this is mostly copied from the expert's guide)\n"
 	     "def @SkribiloLeaders { "
 	     ,leader " |" ,leader-space " @SkribiloLeaders }\n\n"
 
-             "# Embedding an application in PDF (``Launch'' actions)\n"
+             "# Embedding an application in PDF ('Launch' actions)\n"
              "# (tested with XPdf 3.1 and Evince 0.4.0)\n"
              "def @SkribiloEmbed\n"
              "  left command\n"
@@ -1033,7 +1033,7 @@
 	 (which (assoc orientation alist)))
     (if (not which)
 	(skribe-error 'lout
-		      "`page-orientation' should be either `portrait' or `landscape'"
+		      "'page-orientation' should be either 'portrait' or 'landscape'"
 		      orientation)
 	(cdr which))))
 
@@ -1130,7 +1130,7 @@
 		     ((slides)  (display "@SysInclude { slides }\n"))
 		     (else     (skribe-error
 				'lout
-				"`document-type' should be one of `book', `report', `doc' or `slides'"
+				"'document-type' should be one of 'book', 'report', 'doc' or 'slides'"
 				doc-type)))
 		   (format #t "# Custom document includes\n~a\n" doc-include))
 
@@ -1395,7 +1395,7 @@
       ((slides)  (assoc-ref lout-slides-markup-alist skribe-markup))
       (else
        (skribe-error 'lout
-		     "`document-type' should be one of `book', `report', `doc' or `slides'"
+		     "'document-type' should be one of 'book', 'report', 'doc' or 'slides'"
 		     doc-type)))))
 
 
diff --git a/src/guile/skribilo/index.scm b/src/guile/skribilo/index.scm
index 9cdb35e..abdce19 100644
--- a/src/guile/skribilo/index.scm
+++ b/src/guile/skribilo/index.scm
@@ -94,7 +94,7 @@
                                     (location-column loc))
                             ""))
                    (msg (format
-                         #f (_ "the-index: char-offset `~A' out of bounds~%")
+                         #f (_ "the-index: char-offset '~A' out of bounds~%")
                          char-offset)))
                (raise (condition (&message
                                   (condition-message (string-append loc msg))))))
diff --git a/src/guile/skribilo/package/base.scm b/src/guile/skribilo/package/base.scm
index 64d6b97..3941cd1 100644
--- a/src/guile/skribilo/package/base.scm
+++ b/src/guile/skribilo/package/base.scm
@@ -143,7 +143,7 @@
    (let ((body (the-body opts)))
       (cond
 	 (section
-	  (error 'handle "Illegal handle `section' option" section)
+	  (error 'handle "Illegal handle 'section' option" section)
 	  (new unresolved
              (loc  &invocation-location)
 	     (proc (lambda (n e env)
@@ -652,7 +652,7 @@
 		 (if (not (is-markup? r markup))
 		     (skribe-warning 2
 				     for
-				     (format #f "illegal `~a' element, `~a' expected"
+				     (format #f "illegal '~a' element, '~a' expected"
 					     (if (markup? r)
 						 (markup-markup r)
 						 (type-name r))
@@ -813,12 +813,12 @@
 	 ((not (memq align '(#f center left right)))
 	  (skribe-error
 	   'tc
-	   "align should be one of 'left', `center', or `right'"
+	   "align should be one of 'left', 'center', or 'right'"
 	   align))
 	 ((not (memq valign '(#f top middle center bottom)))
 	  (skribe-error
 	   'tc
-	   "valign should be one of 'top', `middle', `center', or `bottom'"
+	   "valign should be one of 'top', 'middle', 'center', or 'bottom'"
 	   valign))
 	 (else
 	  (new container
@@ -1025,7 +1025,7 @@
 	 ((not (string? (car bd)))
 	  (skribe-type-error 'mark "Illegal ident:" (car bd) "string"))
 	 (ident
-	  (skribe-error 'mark "Illegal `ident:' option" ident))
+	  (skribe-error 'mark "Illegal 'ident:' option" ident))
 	 (else
 	  (let* ((bs (ast->string bd))
 		 (n (new markup
@@ -1067,7 +1067,7 @@
 		    (page #f)
                     (sort-bib-refs bib-sort-refs/number))
    (define (unref text kind)
-      (let ((msg (format #f "can't find `~a': " kind)))
+      (let ((msg (format #f "can't find '~a': " kind)))
         (warning/loc 1 &invocation-location 'ref msg text)
         (new markup
              (markup 'unref)
@@ -1230,7 +1230,7 @@
                  (cond
                   ((not target)
                    (skribe-warning/ast 1 n 'numref
-                                       "can't find `ident': "
+                                       "can't find 'ident': "
                                        ident)
                    (new markup
                         (markup 'unref)
@@ -1299,7 +1299,7 @@
                                  (labels 'number))
    (if (not (memq count '(partial full)))
        (skribe-error 'the-bibliography
-		     "count must be either `partial' or `full'"
+		     "count must be either 'partial' or 'full'"
 		     count)
        (let ((label-proc (case labels
                            ((number)    assign-entries-numbers!)
diff --git a/src/guile/skribilo/package/jfp.scm b/src/guile/skribilo/package/jfp.scm
index ee9e118..5c831a2 100644
--- a/src/guile/skribilo/package/jfp.scm
+++ b/src/guile/skribilo/package/jfp.scm
@@ -98,7 +98,7 @@
 			(&latex-author-n body))
 		       (else
 			(skribe-error 'author
-				      "Illegal `jfp' author"
+				      "Illegal 'jfp' author"
 				      body))))))
    ;; title
    (markup-writer '&latex-title le
@@ -171,7 +171,7 @@
 					 (output y e)))))
 			      ((is-markup? y '&bib-entry-year)
 			       (skribe-error 'bib-ref
-					     "Missing `name' entry"
+					     "Missing 'name' entry"
 					     (markup-ident be)))
 			      (else
 			       (let ((ba (markup-body a)))
diff --git a/src/guile/skribilo/package/lncs.scm b/src/guile/skribilo/package/lncs.scm
index 347fd3e..97335e0 100644
--- a/src/guile/skribilo/package/lncs.scm
+++ b/src/guile/skribilo/package/lncs.scm
@@ -146,7 +146,7 @@
 						   (+ 1 j)))))))))
 		       (else
 			(skribe-error 'author
-				      "Illegal `lncs' author"
+				      "Illegal 'lncs' author"
 				      body))))))
    ;; author
    (let ((old-author (markup-writer-get 'author le)))
diff --git a/src/guile/skribilo/package/pie.scm b/src/guile/skribilo/package/pie.scm
index ec68f62..ef21d96 100644
--- a/src/guile/skribilo/package/pie.scm
+++ b/src/guile/skribilo/package/pie.scm
@@ -99,7 +99,7 @@
 	  (weight (and the-slice (markup-option the-slice :weight))))
       (if (not the-slice)
 	  (skribe-error 'lout
-			"`sliceweight' node not within a `slice' body"
+			"'sliceweight' node not within a 'slice' body"
 			sw-node)
 	  (if pct?
 	      (let* ((the-pie (ast-parent the-slice))
@@ -108,7 +108,7 @@
 						'&total-weight))))
 		 (if (not the-pie)
 		     (skribe-error 'lout
-				   "`slice' not within a `pie' body"
+				   "'slice' not within a 'pie' body"
 				   the-slice)
 		     (* 100.0 (/ weight total)))) ;; flonum (FIXME: precision)
 
diff --git a/src/guile/skribilo/package/slide/latex.scm b/src/guile/skribilo/package/slide/latex.scm
index 955a308..1d030c3 100644
--- a/src/guile/skribilo/package/slide/latex.scm
+++ b/src/guile/skribilo/package/slide/latex.scm
@@ -192,7 +192,7 @@
 ;*    %slide-advi-setup! ...                                           */
 ;*---------------------------------------------------------------------*/
 (define (%slide-advi-setup!)
-   (skribe-message "Generating `Advi Seminar' slides...\n")
+   (skribe-message "Generating 'Advi Seminar' slides...\n")
    (let ((le (find-engine 'latex)))
       (define (advi-geometry geo)
 	 (let ((r (string-match "([0-9]+)x([0-9]+)" geo)))
@@ -337,7 +337,7 @@
 ;*    %slide-prosper-setup! ...                                        */
 ;*---------------------------------------------------------------------*/
 (define (%slide-prosper-setup!)
-   (skribe-message "Generating `Prosper' slides...\n")
+   (skribe-message "Generating 'Prosper' slides...\n")
    (let ((le (find-engine 'latex))
 	 (overlay-count 0))
       ;; transitions
diff --git a/src/guile/skribilo/package/web-book2.scm b/src/guile/skribilo/package/web-book2.scm
index 0ce01c5..08ca3ba 100644
--- a/src/guile/skribilo/package/web-book2.scm
+++ b/src/guile/skribilo/package/web-book2.scm
@@ -105,7 +105,7 @@
   ;; Override the `chapter' markup from the `base' package to allow the
   ;; production of a small TOC at the beginning of each chapter.
   (lambda args
-    ;;(format (current-error-port) "in new `~a'~%" markup)
+    ;;(format (current-error-port) "in new '~a'~%" markup)
     (if (engine-format? "html")
         (apply markup
                (append (concatenate (the-options args))
diff --git a/src/guile/skribilo/reader/rss-2.scm b/src/guile/skribilo/reader/rss-2.scm
index 182ebb9..6bdd753 100755
--- a/src/guile/skribilo/reader/rss-2.scm
+++ b/src/guile/skribilo/reader/rss-2.scm
@@ -239,14 +239,14 @@
        `(list ,@(loop (html->shtml body))))
 
       (((? symbol? unsupported-tag) rest ...)
-       (warn* (_ "tag `~s' ignored") tag)
+       (warn* (_ "tag '~s' ignored") tag)
        #f)
 
       ((lst ...)
        (map loop lst))
 
       (_
-       (warn* (_ "skipping tag `~a'~%") tag)
+       (warn* (_ "skipping tag '~a'~%") tag)
        #f))))
 
 (define (english-date->date str)
diff --git a/src/guile/skribilo/source.scm b/src/guile/skribilo/source.scm
index e836af9..39a5eeb 100644
--- a/src/guile/skribilo/source.scm
+++ b/src/guile/skribilo/source.scm
@@ -67,12 +67,12 @@
   ;; Issue a user-friendly error message for error condition C.
   (cond ((no-extractor-error? c)
          (format (current-error-port)
-                 (_ "source language `~a' does not have an extractor~%")
+                 (_ "source language '~a' does not have an extractor~%")
                  (language-name (no-extractor-error:language c))))
 
         ((definition-not-found-error? c)
          (format (current-error-port)
-                 (_ "source definition of `~a' in language `~a' not found~%")
+                 (_ "source definition of '~a' in language '~a' not found~%")
                  (definition-not-found-error:definition c)
                  (language-name (definition-not-found-error:language c))))
 
diff --git a/src/guile/skribilo/utils/compat.scm b/src/guile/skribilo/utils/compat.scm
index 395441b..3f0ec6e 100644
--- a/src/guile/skribilo/utils/compat.scm
+++ b/src/guile/skribilo/utils/compat.scm
@@ -164,7 +164,7 @@
 		   (begin
 		     (if (> (*verbose*) 1)
 			 (format (current-error-port)
-				 "  skribe-load: `~a' -> `~a'~%"
+				 "  skribe-load: '~a' -> '~a'~%"
 				 file mod-name))
 		     (let ((mod (false-if-exception
 				 (resolve-interface mod-name))))
@@ -211,7 +211,7 @@
 		 (*document-being-output*))))
     (if (document? doc)
 	(document-bind-node! doc node)
-	(error "Sorry, unable to achieve `bind-markup!'.  Use `document-bind-node!' instead."
+	(error "Sorry, unable to achieve 'bind-markup!'.  Use 'document-bind-node!' instead."
 	       node))))
 
 (define-public (find-markups ident)
@@ -222,7 +222,7 @@
 	  (if result
 	      (list result)
 	      #f))
-	(error "Sorry, unable to achieve `find-markups'.  Use `document-lookup-node' instead."
+	(error "Sorry, unable to achieve 'find-markups'.  Use 'document-lookup-node' instead."
 	       ident))))
 
 (define-public (find-markup-ident ident)
diff --git a/src/guile/skribilo/verify.scm b/src/guile/skribilo/verify.scm
index 3d38d57..cf07e55 100644
--- a/src/guile/skribilo/verify.scm
+++ b/src/guile/skribilo/verify.scm
@@ -72,7 +72,7 @@
                (option (unsupported-markup-option-error:option c)))
            (show-location node)
 	   (format (current-error-port)
-                   (_ "option `~a' of markup `~a' not supported by engine `~a'~%")
+                   (_ "option '~a' of markup '~a' not supported by engine '~a'~%")
 		   option (and (markup? node)
                                (markup-markup node))
                    (engine-ident engine))))
@@ -127,7 +127,7 @@
 		       3
 		       markup
 		       'verify
-		       (format #f "engine ~a does not support markup ~a option `~a' -- ~a"
+		       (format #f "engine ~a does not support markup ~a option '~a' -- ~a"
 			       (engine-ident engine)
 			       (markup-markup markup)
 			       o
@@ -192,7 +192,7 @@
 	       (skribe-warning/ast
 		     1
 		     node
-		     (format #f "node `~a' forbidden here by ~a engine"
+		     (format #f "node '~a' forbidden here by ~a engine"
 			     (markup-markup node)
 			     (engine-ident e))))))))
      node))