diff --git a/core/ttk.doxygen b/core/ttk.doxygen
index 6ef572d944..14563bd900 100644
--- a/core/ttk.doxygen
+++ b/core/ttk.doxygen
@@ -224,7 +224,7 @@ ALIASES                =
 # A mapping has the form "name=value". For example adding "class=itcl::class"
 # will allow you to use the command class in the itcl::class meaning.
 
-TCL_SUBST              =
+#TCL_SUBST              =
 
 # Set the OPTIMIZE_OUTPUT_FOR_C tag to YES if your project consists of C sources
 # only. Doxygen will then generate output that is more tailored for C. For
@@ -973,7 +973,7 @@ ALPHABETICAL_INDEX     = YES
 # Minimum value: 1, maximum value: 20, default value: 5.
 # This tag requires that the tag ALPHABETICAL_INDEX is set to YES.
 
-COLS_IN_ALPHA_INDEX    = 5
+#COLS_IN_ALPHA_INDEX    = 5
 
 # In case all classes in a project start with a common prefix, all classes will
 # be put under the same header in the alphabetical index. The IGNORE_PREFIX tag
@@ -1783,13 +1783,13 @@ XML_OUTPUT             = xml
 # validating XML parser to check the syntax of the XML files.
 # This tag requires that the tag GENERATE_XML is set to YES.
 
-XML_SCHEMA             =
+# XML_SCHEMA             =
 
 # The XML_DTD tag can be used to specify a XML DTD, which can be used by a
 # validating XML parser to check the syntax of the XML files.
 # This tag requires that the tag GENERATE_XML is set to YES.
 
-XML_DTD                =
+#XML_DTD                =
 
 # If the XML_PROGRAMLISTING tag is set to YES doxygen will dump the program
 # listings (including syntax highlighting and cross-referencing information) to
@@ -1995,7 +1995,7 @@ EXTERNAL_PAGES         = YES
 # interpreter (i.e. the result of 'which perl').
 # The default file (with absolute path) is: /usr/bin/perl.
 
-PERL_PATH              = /usr/bin/perl
+#PERL_PATH              = /usr/bin/perl
 
 #---------------------------------------------------------------------------
 # Configuration options related to the dot tool
@@ -2017,7 +2017,7 @@ CLASS_DIAGRAMS         = YES
 # the mscgen tool resides. If left empty the tool is assumed to be found in the
 # default search path.
 
-MSCGEN_PATH            =
+#MSCGEN_PATH            =
 
 # If set to YES, the inheritance and collaboration graphs will hide inheritance
 # and usage relations if the target is undocumented or is not a class.