diff --git a/docs/awesome_table_in_html.Rmd b/docs/awesome_table_in_html.Rmd
index cfbfddb..9a60fcf 100644
--- a/docs/awesome_table_in_html.Rmd
+++ b/docs/awesome_table_in_html.Rmd
@@ -115,7 +115,7 @@
   add_header_above(c(" " = 1, "Group 1" = 2, "Group 2" = 2, "Group 3" = 2))
 ```
 
-In fact, if you want to add another row of header on top, please feel free to do so. 
+In fact, if you want to add another row of header on top, please feel free to do so.
 ```{r}
 kable(dt) %>%
   kable_styling(c("striped", "bordered")) %>%
@@ -228,23 +228,3 @@
   row_spec(5, bold = T)
 ```
 
-# Add header column to the left
-An alternative way of grouping rows is being added to `kableExtra` 0.3.0. Unlike `group_rows`, the new function `add_header_left` adopts a similar syntax with `add_header_above`. It allows users to add multiple layers of row groups, which is a limitation of `group_rows`. Currently, `add_header_left` in HTML is in good shape with exception that it doesn't work with `group_rows`. 
-```{r}
-mtcars[1:10, 1:6] %>%
-  kable("html") %>%
-  kable_styling()  %>%
-  add_header_above(c(" ", "Data 1" = 3, "Data 2" = 3)) %>%
-  add_header_left(c("Group A" = 3, "Group B" = 2, "Group C" = 4, "Group D" = 1), "Group") %>%
-  add_header_left(c("Team X" = 5, "Team Y" = 5), "Team") %>%
-  add_header_left(c("League Alpha" = 10), "League")
-```
-
-Also, since `col_spec` won't work on these "added" header rows & columns, if you want to bold, italic or specify width for these appended columns, you can define them here. 
-```{r}
-mtcars[1:5, 1:6] %>%
-  kable("html") %>%
-  kable_styling()  %>%
-  add_header_above(c(" ", "Data 1" = 3, "Data 2" = 3)) %>%
-  add_header_left(c("Group A" = 3, "Group B" = 2), "Group", bold = T, width = "10cm")
-```
diff --git a/docs/awesome_table_in_html.html b/docs/awesome_table_in_html.html
index 28dff27..421f706 100644
--- a/docs/awesome_table_in_html.html
+++ b/docs/awesome_table_in_html.html
@@ -3435,491 +3435,6 @@
 </tbody>
 </table>
 </div>
-<div id="add-header-column-to-the-left" class="section level1">
-<h1>Add header column to the left</h1>
-<p>An alternative way of grouping rows is being added to <code>kableExtra</code> 0.3.0. Unlike <code>group_rows</code>, the new function <code>add_header_left</code> adopts a similar syntax with <code>add_header_above</code>. It allows users to add multiple layers of row groups, which is a limitation of <code>group_rows</code>. Currently, <code>add_header_left</code> in HTML is in good shape with exception that it doesn’t work with <code>group_rows</code>.</p>
-<pre class="r"><code>mtcars[1:10, 1:6] %&gt;%
-  kable(&quot;html&quot;) %&gt;%
-  kable_styling()  %&gt;%
-  add_header_above(c(&quot; &quot;, &quot;Data 1&quot; = 3, &quot;Data 2&quot; = 3)) %&gt;%
-  add_header_left(c(&quot;Group A&quot; = 3, &quot;Group B&quot; = 2, &quot;Group C&quot; = 4, &quot;Group D&quot; = 1), &quot;Group&quot;) %&gt;%
-  add_header_left(c(&quot;Team X&quot; = 5, &quot;Team Y&quot; = 5), &quot;Team&quot;) %&gt;%
-  add_header_left(c(&quot;League Alpha&quot; = 10), &quot;League&quot;)</code></pre>
-<?xml version="1.0" encoding="UTF-8" ?>
-<table class="table" style="margin-left: auto; margin-right: auto;">
-<thead>
-<tr>
-<th style="text-align:center; vertical-align: bottom;" rowspan="2">
-League
-</th>
-<th style="text-align:center; vertical-align: bottom;" rowspan="2">
-Team
-</th>
-<th style="text-align:center; vertical-align: bottom;" rowspan="2">
-Group
-</th>
-<th style="border-bottom:hidden"></th>
-<th style="text-align:center; border-bottom:hidden; padding-bottom:0; padding-left:3px;padding-right:3px;" colspan="3">
-<div style="border-bottom: 1px solid #ddd;padding-bottom: 5px;">
-Data 1
-</div>
-</th>
-<th style="text-align:center; border-bottom:hidden; padding-bottom:0; padding-left:3px;padding-right:3px;" colspan="3">
-<div style="border-bottom: 1px solid #ddd;padding-bottom: 5px;">
-Data 2
-</div>
-</th>
-</tr>
-<tr>
-<th style="text-align:left;">
-</th>
-<th style="text-align:right;">
-mpg
-</th>
-<th style="text-align:right;">
-cyl
-</th>
-<th style="text-align:right;">
-disp
-</th>
-<th style="text-align:right;">
-hp
-</th>
-<th style="text-align:right;">
-drat
-</th>
-<th style="text-align:right;">
-wt
-</th>
-</tr>
-</thead>
-<tbody>
-<tr>
-<td style="text-align:center; vertical-align: middle;" rowspan="10">
-League Alpha
-</td>
-<td style="text-align:center; vertical-align: middle;" rowspan="5">
-Team X
-</td>
-<td style="text-align:center; vertical-align: middle;" rowspan="3">
-Group A
-</td>
-<td style="text-align:left;">
-Mazda RX4
-</td>
-<td style="text-align:right;">
-21.0
-</td>
-<td style="text-align:right;">
-6
-</td>
-<td style="text-align:right;">
-160.0
-</td>
-<td style="text-align:right;">
-110
-</td>
-<td style="text-align:right;">
-3.90
-</td>
-<td style="text-align:right;">
-2.620
-</td>
-</tr>
-<tr>
-<td style="text-align:left;">
-Mazda RX4 Wag
-</td>
-<td style="text-align:right;">
-21.0
-</td>
-<td style="text-align:right;">
-6
-</td>
-<td style="text-align:right;">
-160.0
-</td>
-<td style="text-align:right;">
-110
-</td>
-<td style="text-align:right;">
-3.90
-</td>
-<td style="text-align:right;">
-2.875
-</td>
-</tr>
-<tr>
-<td style="text-align:left;">
-Datsun 710
-</td>
-<td style="text-align:right;">
-22.8
-</td>
-<td style="text-align:right;">
-4
-</td>
-<td style="text-align:right;">
-108.0
-</td>
-<td style="text-align:right;">
-93
-</td>
-<td style="text-align:right;">
-3.85
-</td>
-<td style="text-align:right;">
-2.320
-</td>
-</tr>
-<tr>
-<td style="text-align:center; vertical-align: middle;" rowspan="2">
-Group B
-</td>
-<td style="text-align:left;">
-Hornet 4 Drive
-</td>
-<td style="text-align:right;">
-21.4
-</td>
-<td style="text-align:right;">
-6
-</td>
-<td style="text-align:right;">
-258.0
-</td>
-<td style="text-align:right;">
-110
-</td>
-<td style="text-align:right;">
-3.08
-</td>
-<td style="text-align:right;">
-3.215
-</td>
-</tr>
-<tr>
-<td style="text-align:left;">
-Hornet Sportabout
-</td>
-<td style="text-align:right;">
-18.7
-</td>
-<td style="text-align:right;">
-8
-</td>
-<td style="text-align:right;">
-360.0
-</td>
-<td style="text-align:right;">
-175
-</td>
-<td style="text-align:right;">
-3.15
-</td>
-<td style="text-align:right;">
-3.440
-</td>
-</tr>
-<tr>
-<td style="text-align:center; vertical-align: middle;" rowspan="5">
-Team Y
-</td>
-<td style="text-align:center; vertical-align: middle;" rowspan="4">
-Group C
-</td>
-<td style="text-align:left;">
-Valiant
-</td>
-<td style="text-align:right;">
-18.1
-</td>
-<td style="text-align:right;">
-6
-</td>
-<td style="text-align:right;">
-225.0
-</td>
-<td style="text-align:right;">
-105
-</td>
-<td style="text-align:right;">
-2.76
-</td>
-<td style="text-align:right;">
-3.460
-</td>
-</tr>
-<tr>
-<td style="text-align:left;">
-Duster 360
-</td>
-<td style="text-align:right;">
-14.3
-</td>
-<td style="text-align:right;">
-8
-</td>
-<td style="text-align:right;">
-360.0
-</td>
-<td style="text-align:right;">
-245
-</td>
-<td style="text-align:right;">
-3.21
-</td>
-<td style="text-align:right;">
-3.570
-</td>
-</tr>
-<tr>
-<td style="text-align:left;">
-Merc 240D
-</td>
-<td style="text-align:right;">
-24.4
-</td>
-<td style="text-align:right;">
-4
-</td>
-<td style="text-align:right;">
-146.7
-</td>
-<td style="text-align:right;">
-62
-</td>
-<td style="text-align:right;">
-3.69
-</td>
-<td style="text-align:right;">
-3.190
-</td>
-</tr>
-<tr>
-<td style="text-align:left;">
-Merc 230
-</td>
-<td style="text-align:right;">
-22.8
-</td>
-<td style="text-align:right;">
-4
-</td>
-<td style="text-align:right;">
-140.8
-</td>
-<td style="text-align:right;">
-95
-</td>
-<td style="text-align:right;">
-3.92
-</td>
-<td style="text-align:right;">
-3.150
-</td>
-</tr>
-<tr>
-<td style="text-align:center; vertical-align: middle;" rowspan="1">
-Group D
-</td>
-<td style="text-align:left;">
-Merc 280
-</td>
-<td style="text-align:right;">
-19.2
-</td>
-<td style="text-align:right;">
-6
-</td>
-<td style="text-align:right;">
-167.6
-</td>
-<td style="text-align:right;">
-123
-</td>
-<td style="text-align:right;">
-3.92
-</td>
-<td style="text-align:right;">
-3.440
-</td>
-</tr>
-</tbody>
-</table>
-<p>Also, since <code>col_spec</code> won’t work on these “added” header rows &amp; columns, if you want to bold, italic or specify width for these appended columns, you can define them here.</p>
-<pre class="r"><code>mtcars[1:5, 1:6] %&gt;%
-  kable(&quot;html&quot;) %&gt;%
-  kable_styling()  %&gt;%
-  add_header_above(c(&quot; &quot;, &quot;Data 1&quot; = 3, &quot;Data 2&quot; = 3)) %&gt;%
-  add_header_left(c(&quot;Group A&quot; = 3, &quot;Group B&quot; = 2), &quot;Group&quot;, bold = T, width = &quot;10cm&quot;)</code></pre>
-<?xml version="1.0" encoding="UTF-8" ?>
-<table class="table" style="margin-left: auto; margin-right: auto;">
-<thead>
-<tr>
-<th style="text-align:center; vertical-align: bottom;width: 10cm; font-weight: bold; " rowspan="2">
-Group
-</th>
-<th style="border-bottom:hidden"></th>
-<th style="text-align:center; border-bottom:hidden; padding-bottom:0; padding-left:3px;padding-right:3px;" colspan="3">
-<div style="border-bottom: 1px solid #ddd;padding-bottom: 5px;">
-Data 1
-</div>
-</th>
-<th style="text-align:center; border-bottom:hidden; padding-bottom:0; padding-left:3px;padding-right:3px;" colspan="3">
-<div style="border-bottom: 1px solid #ddd;padding-bottom: 5px;">
-Data 2
-</div>
-</th>
-</tr>
-<tr>
-<th style="text-align:left;">
-</th>
-<th style="text-align:right;">
-mpg
-</th>
-<th style="text-align:right;">
-cyl
-</th>
-<th style="text-align:right;">
-disp
-</th>
-<th style="text-align:right;">
-hp
-</th>
-<th style="text-align:right;">
-drat
-</th>
-<th style="text-align:right;">
-wt
-</th>
-</tr>
-</thead>
-<tbody>
-<tr>
-<td style="text-align:center; vertical-align: middle;width: 10cm; font-weight: bold; " rowspan="3">
-Group A
-</td>
-<td style="text-align:left;">
-Mazda RX4
-</td>
-<td style="text-align:right;">
-21.0
-</td>
-<td style="text-align:right;">
-6
-</td>
-<td style="text-align:right;">
-160
-</td>
-<td style="text-align:right;">
-110
-</td>
-<td style="text-align:right;">
-3.90
-</td>
-<td style="text-align:right;">
-2.620
-</td>
-</tr>
-<tr>
-<td style="text-align:left;">
-Mazda RX4 Wag
-</td>
-<td style="text-align:right;">
-21.0
-</td>
-<td style="text-align:right;">
-6
-</td>
-<td style="text-align:right;">
-160
-</td>
-<td style="text-align:right;">
-110
-</td>
-<td style="text-align:right;">
-3.90
-</td>
-<td style="text-align:right;">
-2.875
-</td>
-</tr>
-<tr>
-<td style="text-align:left;">
-Datsun 710
-</td>
-<td style="text-align:right;">
-22.8
-</td>
-<td style="text-align:right;">
-4
-</td>
-<td style="text-align:right;">
-108
-</td>
-<td style="text-align:right;">
-93
-</td>
-<td style="text-align:right;">
-3.85
-</td>
-<td style="text-align:right;">
-2.320
-</td>
-</tr>
-<tr>
-<td style="text-align:center; vertical-align: middle;width: 10cm; font-weight: bold; " rowspan="2">
-Group B
-</td>
-<td style="text-align:left;">
-Hornet 4 Drive
-</td>
-<td style="text-align:right;">
-21.4
-</td>
-<td style="text-align:right;">
-6
-</td>
-<td style="text-align:right;">
-258
-</td>
-<td style="text-align:right;">
-110
-</td>
-<td style="text-align:right;">
-3.08
-</td>
-<td style="text-align:right;">
-3.215
-</td>
-</tr>
-<tr>
-<td style="text-align:left;">
-Hornet Sportabout
-</td>
-<td style="text-align:right;">
-18.7
-</td>
-<td style="text-align:right;">
-8
-</td>
-<td style="text-align:right;">
-360
-</td>
-<td style="text-align:right;">
-175
-</td>
-<td style="text-align:right;">
-3.15
-</td>
-<td style="text-align:right;">
-3.440
-</td>
-</tr>
-</tbody>
-</table>
-</div>
 
 
 
diff --git a/docs/awesome_table_in_pdf.Rmd b/docs/awesome_table_in_pdf.Rmd
index d05733e..351686b 100644
--- a/docs/awesome_table_in_pdf.Rmd
+++ b/docs/awesome_table_in_pdf.Rmd
@@ -128,13 +128,13 @@
   add_header_above(c(" " = 1, "Group 1" = 2, "Group 2" = 2, "Group 3" = 2))
 ```
 
-In fact, if you want to add another row of header on top, please feel free to do so. 
+In fact, if you want to add another row of header on top, please feel free to do so. Also, in kableExtra 0.3.0, you can specify `bold` & `italic` as you do in `row_spec()`.
 ```{r}
 kable(dt, booktabs = T) %>%
   kable_styling() %>%
   add_header_above(c(" ", "Group 1" = 2, "Group 2" = 2, "Group 3" = 2)) %>%
   add_header_above(c(" ", "Group 4" = 4, "Group 5" = 2)) %>%
-  add_header_above(c(" ", "Group 6" = 6))
+  add_header_above(c(" ", "Group 6" = 6), bold = T, italic = T)
 ```
 
 # Add footnote
@@ -252,15 +252,3 @@
   row_spec(5, bold = T)
 ```
 
-# Add header column to the left
-An alternative way of grouping rows is being added to `kableExtra` 0.3.0. Unlike `group_rows`, the new function `add_header_left` adopts a similar syntax with `add_header_above`. It allows users to add multiple layers of row groups, which is a limitation of `group_rows`. One limitation of `add_header_left` is that, you can only use it in `booktabs` tables. There is no future plan to extend support to LaTeX table without booktabs because it is techinically very difficult. Other limitations include incompatible with `group_rows` and a little in-stable `striped` row coloring behavior. If you don't have special need for multiple layers of heading columns or special love to this format, I will recommend you stick with `group_rows`. 
-
-```{r}
-mtcars[1:10, 1:6] %>%
-  kable("latex", booktabs= T) %>%
-  add_header_above(c(" ", "Data 1" = 3, "Data 2" = 3)) %>%
-  add_header_left(c("Group A" = 3, "Group B" = 2, "Group C" = 4, "Group D" = 1), "Group") %>%
-  add_header_left(c("Team X" = 5, "Team Y" = 5), "Team", full_midline = T) %>%
-  add_header_left(c("League Alpha" = 10), "League") %>%
-  column_spec(1, bold = T)
-```
diff --git a/docs/awesome_table_in_pdf.pdf b/docs/awesome_table_in_pdf.pdf
index cdd9be6..037484d 100644
--- a/docs/awesome_table_in_pdf.pdf
+++ b/docs/awesome_table_in_pdf.pdf
Binary files differ