diff --git a/linkchecker b/linkchecker
index e1110c74..bc1ce874 100755
--- a/linkchecker
+++ b/linkchecker
@@ -38,7 +38,8 @@ OPTIONS
 For single-letter option arguments the space is not a necessity. So
 '-o colored' is the same as '-ocolored'.
 -a, --anchors
-        Check HTTP anchor references. Default is don't check anchors.
+        Check HTTP anchor references. This option applies to both intern
+        and extern urls. Default is don't check anchors.
         This option implies -w because anchor errors are always warnings.
 -C, --cookies
         Accept and send HTTP cookies according to RFC 2109. Only cookies
@@ -75,7 +76,7 @@ For single-letter option arguments the space is not a necessity. So
         Specify an NNTP server for 'news:...' links. Default is the
         environment variable NNTP_SERVER. If no host is given,
         only the syntax of the link is checked.
--no-anchor-caching
+--no-anchor-caching
         Treat url#anchora and url#anchorb as equal on caching. This
         is the default browser behaviour, but it's not specified in
         the URI specification. Use with care.
@@ -365,6 +366,9 @@ for opt,arg in options:
         except ValueError:
             printUsage(i18n._("Illegal argument %s for option %s") % \
                        (`arg`, "'--timeout'"))
+        if timeout <= 0:
+            printUsage(i18n._("Illegal argument %s for option %s") % \
+                       (`arg`, "'--timeout'"))
         linkcheck.timeoutsocket.setDefaultSocketTimeout(timeout)
 
     elif opt=="-u" or opt=="--user":
diff --git a/linkchecker.1 b/linkchecker.1
index 6039efc6..9a33aa44 100644
--- a/linkchecker.1
+++ b/linkchecker.1
@@ -30,7 +30,9 @@ For single-letter option arguments the space is not a necessity.
 So \fI-o colored\fP is the same as \fI-ocolored\fP.
 .TP
 \fB-a\fP, \fB--anchors\fP
-Check HTTP anchor references. Default is don't check anchors.
+Check HTTP anchor references.  This option applies to both intern
+and extern urls. Default is don't check anchors.
+This option implies -w because anchor errors are always warnings.
 .TP
 \fB-C\fP, \fB--cookies\fP
 Accept and send HTTP cookies according to RFC 2109. Only cookies
@@ -76,6 +78,11 @@ Specify an NNTP server for 'news:...' links. Default is the
 environment variable NNTP_SERVER. If no host is given,
 only the syntax of the link is checked.
 .TP
+\fB--no-anchor-caching\fP
+Treat url#anchora and url#anchorb as equal on caching. This
+is the default browser behaviour, but it's not specified in
+the URI specification. Use with care.
+.TP
 \fB-o \fItype\fP, \fB--output=\fItype\fP
 Specify output type as \fItext\fP, \fIcolored\fP, \fIhtml\fP, \fIsql\fP,
 \fIcsv\fP, \fIgml\fP, \fIxml\fP or \fIblacklist\fP.