diff --git a/.remarkrc b/.remarkrc
index 7f65681..2f490dd 100644
--- a/.remarkrc
+++ b/.remarkrc
@@ -2,6 +2,7 @@
   "plugins": [
     "remark-preset-lint-markdown-style-guide",
     ["remark-lint-list-item-spacing", false],
-    ["remark-lint-maximum-line-length", false]
+    ["remark-lint-maximum-line-length", false],
+    ["remark-lint-no-duplicate-headings", false],
   ]
-}
\ No newline at end of file
+}
diff --git a/bin/generate_readme.sh b/bin/generate_readme.sh
index c143e33..5276fd5 100755
--- a/bin/generate_readme.sh
+++ b/bin/generate_readme.sh
@@ -4,7 +4,7 @@ README="README.md"
 _setup() {
     INVALID_CHARS="'[]/?!:\`.,()*\";{}+=<>~$|#@&–—"
     MINLEVEL=1
-    MAXLEVEL=2
+    MAXLEVEL=3
     SCRIPT_FILE=$(basename $0)
     SCRIPT_FILENAME="${SCRIPT_FILE%.*}"
     rm README.md
@@ -103,7 +103,7 @@ _insert_toc_to_file() {
     declare info_toc="<!-- DO NOT EDIT THIS SECTION, INSTEAD RE-RUN ${SCRIPT_FILE} TO UPDATE -->"
     declare end_toc="<!-- END ${SCRIPT_FILE} generated TOC please keep comment here to allow auto update -->"
 
-    toc_block="$start_toc\n$info_toc\n**Table of Contents**\n\n$toc_text\n$end_toc"
+    toc_block="$start_toc\n$info_toc\n## Table of Contents\n\n$toc_text\n$end_toc"
 
     # temporary replace of '/' (confused with separator of substitutions) and '&' (confused with match regex symbol) to run the special sed command
     utext_ampersand="id8234923000230gzz"
@@ -114,12 +114,14 @@ _insert_toc_to_file() {
     # search multiline toc block -> https://stackoverflow.com/questions/2686147/how-to-find-patterns-across-multiple-lines-using-grep/2686705
     # grep color for debugging -> https://superuser.com/questions/914856/grep-display-all-output-but-highlight-search-matches
     if grep --color=always -Pzl "(?s)$start_toc.*\n.*$end_toc" $1 &> /dev/null; then
-        echo -e "\n  Updated content of $appname block in $1 succesfully\n"
         # src https://askubuntu.com/questions/533221/how-do-i-replace-multiple-lines-with-single-word-in-fileinplace-replace
         sed -i ":a;N;\$!ba;s/$start_toc.*$end_toc/$toc_block/g" $1
+        echo -e "\n  Updated TOC content in $1 succesfully\n"
+
     else
-        echo -e "\n  Created $appname block in $1 succesfully\n"
         sed -i 1i"$toc_block" "$1"
+        echo -e "\n  Created TOC in $1 succesfully\n"
+
     fi
 
     # undo symbol replacements
diff --git a/bin/shdoc.awk b/bin/shdoc.awk
index 01bafc9..67fb819 100755
--- a/bin/shdoc.awk
+++ b/bin/shdoc.awk
@@ -59,7 +59,7 @@ function reset() {
 
 /^[[:space:]]*# @file/ {
     sub(/^[[:space:]]*# @file /, "")
-    filedoc = render("h1", $0) "\n"
+    filedoc = render("h2", $0) "\n"
 }
 
 /^[[:space:]]*# @brief/ {
@@ -106,7 +106,7 @@ in_example {
 /^[[:space:]]*# @example/ {
     in_example = 1
 
-    docblock = docblock "\n" render("h3", "Example")
+    docblock = docblock "\n" render("h4", "Example")
     docblock = docblock "\n\n" render("code", "bash")
 }
 
@@ -114,7 +114,7 @@ in_example {
     if (!has_args) {
         has_args = 1
 
-        docblock = docblock "\n" render("h3", "Arguments") "\n\n"
+        docblock = docblock "\n" render("h4", "Arguments") "\n\n"
     }
 
     sub(/^[[:space:]]*# @arg /, "")
@@ -133,7 +133,7 @@ in_example {
     if (!has_exitcode) {
         has_exitcode = 1
 
-        docblock = docblock "\n" render("h3", "Exit codes") "\n\n"
+        docblock = docblock "\n" render("h4", "Exit codes") "\n\n"
     }
 
     sub(/^[[:space:]]*# @exitcode /, "")
@@ -157,7 +157,7 @@ in_example {
 
     sub(/^[[:space:]]*# @stdout /, "")
 
-    docblock = docblock "\n" render("h3", "Output on stdout")
+    docblock = docblock "\n" render("h4", "Output on stdout")
     docblock = docblock "\n\n" render("li", $0) "\n"
 }
 
@@ -171,15 +171,15 @@ in_example {
             "g" \
         )
 
-        doc = doc "\n" render("h2", func_name) "\n" docblock
+        doc = doc "\n" render("h3", func_name) "\n" docblock
 
-        url = func_name
-        # https://github.com/jch/html-pipeline/blob/master/lib/html/pipeline/toc_filter.rb#L44-L45
-        url = tolower(url)
-        gsub(/[^[:alnum:] -]/, "", url)
-        gsub(/ /, "-", url)
+        # url = func_name
+        # # https://github.com/jch/html-pipeline/blob/master/lib/html/pipeline/toc_filter.rb#L44-L45
+        # url = tolower(url)
+        # gsub(/[^[:alnum:] -]/, "", url)
+        # gsub(/ /, "-", url)
 
-        toc = toc "\n" "- [" func_name "](#" url ")"
+        # toc = toc "\n" "- [" func_name "](#" url ")"
     }
 
     docblock = ""
@@ -190,7 +190,7 @@ END {
     if (filedoc != "") {
         print filedoc
     }
-    print toc
-    print ""
+    #print toc
+   # print ""
     print doc
 }
diff --git a/src/string.sh b/src/string.sh
index e244e13..0a62c5c 100644
--- a/src/string.sh
+++ b/src/string.sh
@@ -101,7 +101,7 @@ string::to_lower() {
     if [[ ${BASH_VERSINFO:-0} -ge 4 ]]; then
         printf '%s\n' "${1,,}"
     else
-        printf "${@}\n" | tr '[A-Z]' '[a-z]'
+        printf "%s\n" "${@}" | tr 'A-Z' 'a-z'
     fi
 }
 
@@ -123,7 +123,7 @@ string::to_upper() {
     if [[ ${BASH_VERSINFO:-0} -ge 4 ]]; then
         printf '%s\n' "${1^^}"
     else
-        printf "${@}\n" | tr '[a-z]' '[A-Z]'
+        printf "%s\n" "${@}" | tr 'a-z' 'A-Z'
     fi
 }