diff --git a/DESCRIPTION b/DESCRIPTION
index e522975..0a4d476 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: kableExtra
 Type: Package
 Title: Construct Complex Table with 'kable' and Pipe Syntax
-Version: 0.5.1
+Version: 0.5.1.9000
 Authors@R: c(
     person('Hao', 'Zhu', email = 'haozhu233@gmail.com', role = c('aut', 'cre')),
     person('Timothy', 'Tsai', role = 'ctb'),
diff --git a/docs/awesome_table_in_html.Rmd b/docs/awesome_table_in_html.Rmd
index 96baeda..95c745e 100644
--- a/docs/awesome_table_in_html.Rmd
+++ b/docs/awesome_table_in_html.Rmd
@@ -37,7 +37,7 @@
 dt <- mtcars[1:5, 1:6]
 ```
 
-When you are using `kable()`, if you don't specify `format`, by default it will generate a markdown table and let pandoc handle the conversion from markdown to HTML/PDF. This is the most favorable approach to render most simple tables as it is format independent. If you switch from HTML to pdf, you basically don't need to change anything in your code. However, markdown doesn't support complex table. For example, if you want to have a double-row header table, markdown just cannot provide you the functionality you need. As a result, when you have such a need, you should **define `format` in `kable()`** as either "html" or "latex". *You can also define a global option at the beginning using `options(knitr.table.format = "html")` so you don't repeat the step everytime.*
+When you are using `kable()`, if you don't specify `format`, by default it will generate a markdown table and let pandoc handle the conversion from markdown to HTML/PDF. This is the most favorable approach to render most simple tables as it is format independent. If you switch from HTML to pdf, you basically don't need to change anything in your code. However, markdown doesn't support complex table. For example, if you want to have a double-row header table, markdown just cannot provide you the functionality you need. As a result, when you have such a need, you should **define `format` in `kable()`** as either "html" or "latex". *You can also define a global option at the beginning using `options(knitr.table.format = "html")` so you don't repeat the step everytime.* **In this tutorial, I'll still put `format="html"` in the function in case users just want to quickly replicate the results.** 
 
 ```{r}
 options(knitr.table.format = "html") 
@@ -47,13 +47,14 @@
 ## Basic HTML table
 Basic HTML output of `kable` looks very crude. To the end, it's just a plain HTML table without any love from css.
 ```{r}
-kable(dt)
+kable(dt, "html")
 ```
 
 ## Bootstrap theme
 When used on a HTML table, `kable_styling()` will automatically apply twitter bootstrap theme to the table. Now it should looks the same as the original pandoc output (the one when you don't specify `format` in `kable()`) but this time, you are controlling it.
 ```{r}
-kable(dt) %>%
+dt %>%
+  kable("html") %>%
   kable_styling()
 ```
 
@@ -65,39 +66,39 @@
 
 For example, to add striped lines (alternative row colors) to your table and you want to highlight the hovered row, you can simply type:
 ```{r}
-kable(dt) %>%
+kable(dt, "html") %>%
   kable_styling(bootstrap_options = c("striped", "hover"))
 ```
 
 The option `condensed` can also be handy in many cases when you don't want your table to be too large. It has slightly shorter row height.
 ```{r}
-kable(dt) %>%
+kable(dt, "html") %>%
   kable_styling(bootstrap_options = c("striped", "hover", "condensed"))
 ```
 
 Tables with option `responsive` looks the same with others on a large screen. However, on a small screen like phone, they are horizontally scrollable. Please resize your window to see the result.
 ```{r}
-kable(dt) %>%
+kable(dt, "html") %>%
   kable_styling(bootstrap_options = c("striped", "hover", "condensed", "responsive"))
 ```
 
 ## Full width?
 By default, a bootstrap table takes 100% of the width. It is supposed to use together with its grid system to scale the table properly. However, when you are writing a rmarkdown document, you probably don't want to write your own css/or grid. For some small tables with only few columns, a page wide table looks awful. To make it easier, you can specify whether you want the table to have  `full_width` or not in `kable_styling`. By default, `full_width` is set to be `TRUE` for HTML tables (note that for LaTeX, the default is `FALSE` since I don't want to change the "common" looks unless you specified it.)
 ```{r}
-kable(dt) %>%
+kable(dt, "html") %>%
   kable_styling(bootstrap_options = "striped", full_width = F)
 ```
 
 ## Position
 Table Position only matters when the table doesn't have `full_width`. You can choose to align the table to `center`, `left` or `right` side of the page
 ```{r}
-kable(dt) %>%
+kable(dt, "html") %>%
   kable_styling(bootstrap_options = "striped", full_width = F, position = "left")
 ```
 
 Becides these three common options, you can also wrap text around the table using the `float-left` or `float-right` options. 
 ```{r}
-kable(dt) %>%
+kable(dt, "html") %>%
   kable_styling(bootstrap_options = "striped", full_width = F, position = "float_right")
 ```
 Lorem ipsum dolor sit amet, consectetur adipiscing elit. Cras sit amet mauris in ex ultricies elementum vel rutrum dolor. Phasellus tempor convallis dui, in hendrerit mauris placerat scelerisque. Maecenas a accumsan enim, a maximus velit. Pellentesque in risus eget est faucibus convallis nec at nulla. Phasellus nec lacinia justo. Morbi fermentum, orci id varius accumsan, nibh neque porttitor ipsum, consectetur luctus risus arcu ac ex. Aenean a luctus augue. Suspendisse et auctor nisl. Suspendisse cursus ultrices quam non vulputate. Phasellus et pharetra neque, vel feugiat erat. Sed feugiat elit at mauris commodo consequat. Sed congue lectus id mattis hendrerit. Mauris turpis nisl, congue eget velit sed, imperdiet convallis magna. Nam accumsan urna risus, non feugiat odio vehicula eget.
@@ -105,7 +106,7 @@
 ## Font size
 If one of your tables is huge and you want to use a smaller font size for that specific table, you can use the `font_size` option. 
 ```{r}
-kable(dt) %>%
+kable(dt, "html") %>%
   kable_styling(bootstrap_options = "striped", font_size = 7)
 ```
 
@@ -125,7 +126,7 @@
   )
 )
 
-kable(text_tbl) %>%
+kable(text_tbl, "html") %>%
   kable_styling(full_width = F) %>%
   column_spec(1, bold = T, border_right = T) %>%
   column_spec(2, width = "30em", background = "yellow")
@@ -136,7 +137,7 @@
 Similar with `column_spec`, you can define specifications for rows. Currently, you can either bold or italiciz an entire row. Note that, similar with other row-related functions in `kableExtra`, for the position of the target row, you don't need to count in header rows or the group labelling rows.
 
 ```{r}
-kable(dt) %>%
+kable(dt, "html") %>%
   kable_styling("striped", full_width = F) %>%
   column_spec(7, bold = T) %>%
   row_spec(5, bold = T, color = "white", background = "#D7261E")
@@ -146,14 +147,14 @@
 ## Add header rows to group columns
 Tables with multi-row headers can be very useful to demonstrate grouped data. To do that, you can pipe your kable object into `add_header_above()`. The header variable is supposed to be a named character with the names as new column names and values as column span. For your convenience, if column span equals to 1, you can ignore the `=1` part so the function below can be written as `add_header_above(c(" ", "Group 1" = 2, "Group 2" = 2, "Group 3" = 2)).
 ```{r}
-kable(dt) %>%
+kable(dt, "html") %>%
   kable_styling("striped") %>%
   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.
 ```{r}
-kable(dt) %>%
+kable(dt, "html") %>%
   kable_styling(c("striped", "bordered")) %>%
   add_header_above(c(" ", "Group 1" = 2, "Group 2" = 2, "Group 3" = 2)) %>%
   add_header_above(c(" ", "Group 4" = 4, "Group 5" = 2)) %>%
@@ -163,7 +164,7 @@
 ## Group rows via labeling
 Sometimes we want a few rows of the table being grouped together. They might be items under the same topic (e.g., animals in one species) or just different data groups for a categorical variable (e.g., age < 40, age > 40). With the new function `group_rows()` in `kableExtra`, this kind of task can be completed in one line. Please see the example below. Note that when you count for the start/end rows of the group, you don't need to count for the header rows nor other group label rows. You only need to think about the row numbers in the "original R dataframe".
 ```{r}
-kable(mtcars[1:10, 1:6], caption = "Group Rows") %>%
+kable(mtcars[1:10, 1:6], "html", caption = "Group Rows") %>%
   kable_styling("striped", full_width = F) %>%
   group_rows("Group 1", 4, 7) %>%
   group_rows("Group 2", 8, 10)
@@ -171,7 +172,7 @@
 
 For advanced users, you can even define your own css for the group labeling.
 ```{r}
-kable(dt) %>%
+kable(dt, "html") %>%
   kable_styling("striped", full_width = F) %>%
   group_rows("Group 1", 3, 5, label_row_css = "background-color: #666; color: #fff;")
 ```
@@ -180,7 +181,7 @@
 Unlike `group_rows()`, which will insert a labeling row, sometimes we want to list a few sub groups under a total one. In that case, `add_indent()` is probably more apporiate. 
 For advanced users, you can even define your own css for the group labeling.
 ```{r}
-kable(dt) %>%
+kable(dt, "html") %>%
   kable_styling("striped", full_width = F) %>%
   add_indent(c(1, 3, 5))
 ```
@@ -205,21 +206,21 @@
 
 ### Alphabet
 ```{r}
-kable(dt) %>%
+kable(dt, "html") %>%
   kable_styling("striped") %>%
   add_footnote(c("Footnote 1", "Have a good day."), notation = "alphabet")
 ```
 
 ### Number
 ```{r}
-kable(dt) %>%
+kable(dt, "html") %>%
   kable_styling("striped") %>%
   add_footnote(c("Footnote 1", "Have a good day."), notation = "number")
 ```
 
 ### Symbol
 ```{r}
-kable(dt) %>%
+kable(dt, "html") %>%
   kable_styling("striped") %>%
   add_footnote(c("Footnote 1", "Footnote 2", "Footnote 3"), notation = "symbol")
 ```
@@ -228,7 +229,7 @@
 By design, `add_footnote()` will transform any `[note]` to in-table footnote markers. 
 
 ```{r}
-kable(dt, caption = "Demo Table[note]") %>%
+kable(dt, "html", caption = "Demo Table[note]") %>%
   kable_styling("striped") %>%
   add_header_above(c(" ", "Group 1[note]" = 3, "Group 2[note]" = 3)) %>%
   add_footnote(c("This table is from mtcars", 
@@ -244,7 +245,7 @@
 When you use `scroll_box`, you can specify either `height` or `width`. When you specify `height`, you will get a vertically scrollable box and vice versa. If you specify both, you will get a two-way scrollable box. 
 
 ```{r}
-kable(cbind(mtcars, mtcars)) %>%
+kable(cbind(mtcars, mtcars), "html") %>%
   kable_styling() %>%
   scroll_box(width = "500px", height = "200px")
 ```
diff --git a/docs/awesome_table_in_html.html b/docs/awesome_table_in_html.html
index 15e4da9..3b0c3ad 100644
--- a/docs/awesome_table_in_html.html
+++ b/docs/awesome_table_in_html.html
@@ -11,7 +11,7 @@
 
 <meta name="author" content="Hao Zhu" />
 
-<meta name="date" content="2017-09-05" />
+<meta name="date" content="2017-09-13" />
 
 <title>Create Awesome HTML Table with knitr::kable and kableExtra</title>
 
@@ -217,7 +217,7 @@
 
 <h1 class="title toc-ignore">Create Awesome HTML Table with knitr::kable and kableExtra</h1>
 <h4 class="author"><em>Hao Zhu</em></h4>
-<h4 class="date"><em>2017-09-05</em></h4>
+<h4 class="date"><em>2017-09-13</em></h4>
 
 </div>
 
@@ -245,13 +245,13 @@
 <pre><code>## Warning: package 'knitr' was built under R version 3.4.1</code></pre>
 <pre class="r"><code>library(kableExtra)
 dt &lt;- mtcars[1:5, 1:6]</code></pre>
-<p>When you are using <code>kable()</code>, if you don’t specify <code>format</code>, by default it will generate a markdown table and let pandoc handle the conversion from markdown to HTML/PDF. This is the most favorable approach to render most simple tables as it is format independent. If you switch from HTML to pdf, you basically don’t need to change anything in your code. However, markdown doesn’t support complex table. For example, if you want to have a double-row header table, markdown just cannot provide you the functionality you need. As a result, when you have such a need, you should <strong>define <code>format</code> in <code>kable()</code></strong> as either “html” or “latex”. <em>You can also define a global option at the beginning using <code>options(knitr.table.format = &quot;html&quot;)</code> so you don’t repeat the step everytime.</em></p>
+<p>When you are using <code>kable()</code>, if you don’t specify <code>format</code>, by default it will generate a markdown table and let pandoc handle the conversion from markdown to HTML/PDF. This is the most favorable approach to render most simple tables as it is format independent. If you switch from HTML to pdf, you basically don’t need to change anything in your code. However, markdown doesn’t support complex table. For example, if you want to have a double-row header table, markdown just cannot provide you the functionality you need. As a result, when you have such a need, you should <strong>define <code>format</code> in <code>kable()</code></strong> as either “html” or “latex”. <em>You can also define a global option at the beginning using <code>options(knitr.table.format = &quot;html&quot;)</code> so you don’t repeat the step everytime.</em> <strong>In this tutorial, I’ll still put <code>format=&quot;html&quot;</code> in the function in case users just want to quickly replicate the results.</strong></p>
 <pre class="r"><code>options(knitr.table.format = &quot;html&quot;) 
 ## If you don't define format here, you'll need put `format = &quot;html&quot;` in every kable function.</code></pre>
 <div id="basic-html-table" class="section level2">
 <h2>Basic HTML table</h2>
 <p>Basic HTML output of <code>kable</code> looks very crude. To the end, it’s just a plain HTML table without any love from css.</p>
-<pre class="r"><code>kable(dt)</code></pre>
+<pre class="r"><code>kable(dt, &quot;html&quot;)</code></pre>
 <table>
 <thead>
 <tr>
@@ -399,7 +399,8 @@
 <div id="bootstrap-theme" class="section level2">
 <h2>Bootstrap theme</h2>
 <p>When used on a HTML table, <code>kable_styling()</code> will automatically apply twitter bootstrap theme to the table. Now it should looks the same as the original pandoc output (the one when you don’t specify <code>format</code> in <code>kable()</code>) but this time, you are controlling it.</p>
-<pre class="r"><code>kable(dt) %&gt;%
+<pre class="r"><code>dt %&gt;%
+  kable(&quot;html&quot;) %&gt;%
   kable_styling()</code></pre>
 <table class="table" style="margin-left: auto; margin-right: auto;">
 <thead>
@@ -553,7 +554,7 @@
 <h2>Bootstrap table classes</h2>
 <p>If you are familiar with twitter bootstrap, you probably have already known its predefined classes, including <code>striped</code>, <code>bordered</code>, <code>hover</code>, <code>condensed</code> and <code>responsive</code>. If you are not familiar, no worries, you can take a look at their <a href="http://getbootstrap.com/css/#tables">documentation site</a> to get a sense of how they look like. All of these options are available here.</p>
 <p>For example, to add striped lines (alternative row colors) to your table and you want to highlight the hovered row, you can simply type:</p>
-<pre class="r"><code>kable(dt) %&gt;%
+<pre class="r"><code>kable(dt, &quot;html&quot;) %&gt;%
   kable_styling(bootstrap_options = c(&quot;striped&quot;, &quot;hover&quot;))</code></pre>
 <table class="table table-striped table-hover" style="margin-left: auto; margin-right: auto;">
 <thead>
@@ -699,7 +700,7 @@
 </tbody>
 </table>
 <p>The option <code>condensed</code> can also be handy in many cases when you don’t want your table to be too large. It has slightly shorter row height.</p>
-<pre class="r"><code>kable(dt) %&gt;%
+<pre class="r"><code>kable(dt, &quot;html&quot;) %&gt;%
   kable_styling(bootstrap_options = c(&quot;striped&quot;, &quot;hover&quot;, &quot;condensed&quot;))</code></pre>
 <table class="table table-striped table-hover table-condensed" style="margin-left: auto; margin-right: auto;">
 <thead>
@@ -845,7 +846,7 @@
 </tbody>
 </table>
 <p>Tables with option <code>responsive</code> looks the same with others on a large screen. However, on a small screen like phone, they are horizontally scrollable. Please resize your window to see the result.</p>
-<pre class="r"><code>kable(dt) %&gt;%
+<pre class="r"><code>kable(dt, &quot;html&quot;) %&gt;%
   kable_styling(bootstrap_options = c(&quot;striped&quot;, &quot;hover&quot;, &quot;condensed&quot;, &quot;responsive&quot;))</code></pre>
 <table class="table table-striped table-hover table-condensed table-responsive" style="margin-left: auto; margin-right: auto;">
 <thead>
@@ -994,7 +995,7 @@
 <div id="full-width" class="section level2">
 <h2>Full width?</h2>
 <p>By default, a bootstrap table takes 100% of the width. It is supposed to use together with its grid system to scale the table properly. However, when you are writing a rmarkdown document, you probably don’t want to write your own css/or grid. For some small tables with only few columns, a page wide table looks awful. To make it easier, you can specify whether you want the table to have <code>full_width</code> or not in <code>kable_styling</code>. By default, <code>full_width</code> is set to be <code>TRUE</code> for HTML tables (note that for LaTeX, the default is <code>FALSE</code> since I don’t want to change the “common” looks unless you specified it.)</p>
-<pre class="r"><code>kable(dt) %&gt;%
+<pre class="r"><code>kable(dt, &quot;html&quot;) %&gt;%
   kable_styling(bootstrap_options = &quot;striped&quot;, full_width = F)</code></pre>
 <table class="table table-striped" style="width: auto !important; margin-left: auto; margin-right: auto;">
 <thead>
@@ -1143,7 +1144,7 @@
 <div id="position" class="section level2">
 <h2>Position</h2>
 <p>Table Position only matters when the table doesn’t have <code>full_width</code>. You can choose to align the table to <code>center</code>, <code>left</code> or <code>right</code> side of the page</p>
-<pre class="r"><code>kable(dt) %&gt;%
+<pre class="r"><code>kable(dt, &quot;html&quot;) %&gt;%
   kable_styling(bootstrap_options = &quot;striped&quot;, full_width = F, position = &quot;left&quot;)</code></pre>
 <table class="table table-striped" style="width: auto !important; ">
 <thead>
@@ -1289,7 +1290,7 @@
 </tbody>
 </table>
 <p>Becides these three common options, you can also wrap text around the table using the <code>float-left</code> or <code>float-right</code> options.</p>
-<pre class="r"><code>kable(dt) %&gt;%
+<pre class="r"><code>kable(dt, &quot;html&quot;) %&gt;%
   kable_styling(bootstrap_options = &quot;striped&quot;, full_width = F, position = &quot;float_right&quot;)</code></pre>
 <table class="table table-striped" style="width: auto !important; float: right; margin-left: 10px;">
 <thead>
@@ -1439,7 +1440,7 @@
 <div id="font-size" class="section level2">
 <h2>Font size</h2>
 <p>If one of your tables is huge and you want to use a smaller font size for that specific table, you can use the <code>font_size</code> option.</p>
-<pre class="r"><code>kable(dt) %&gt;%
+<pre class="r"><code>kable(dt, &quot;html&quot;) %&gt;%
   kable_styling(bootstrap_options = &quot;striped&quot;, font_size = 7)</code></pre>
 <table class="table table-striped" style="font-size: 7px; margin-left: auto; margin-right: auto;">
 <thead>
@@ -1601,7 +1602,7 @@
   )
 )
 
-kable(text_tbl) %&gt;%
+kable(text_tbl, &quot;html&quot;) %&gt;%
   kable_styling(full_width = F) %&gt;%
   column_spec(1, bold = T, border_right = T) %&gt;%
   column_spec(2, width = &quot;30em&quot;, background = &quot;yellow&quot;)</code></pre>
@@ -1647,7 +1648,7 @@
 <div id="row-spec" class="section level2">
 <h2>Row spec</h2>
 <p>Similar with <code>column_spec</code>, you can define specifications for rows. Currently, you can either bold or italiciz an entire row. Note that, similar with other row-related functions in <code>kableExtra</code>, for the position of the target row, you don’t need to count in header rows or the group labelling rows.</p>
-<pre class="r"><code>kable(dt) %&gt;%
+<pre class="r"><code>kable(dt, &quot;html&quot;) %&gt;%
   kable_styling(&quot;striped&quot;, full_width = F) %&gt;%
   column_spec(7, bold = T) %&gt;%
   row_spec(5, bold = T, color = &quot;white&quot;, background = &quot;#D7261E&quot;)</code></pre>
@@ -1801,7 +1802,7 @@
 <div id="add-header-rows-to-group-columns" class="section level2">
 <h2>Add header rows to group columns</h2>
 <p>Tables with multi-row headers can be very useful to demonstrate grouped data. To do that, you can pipe your kable object into <code>add_header_above()</code>. The header variable is supposed to be a named character with the names as new column names and values as column span. For your convenience, if column span equals to 1, you can ignore the <code>=1</code> part so the function below can be written as `add_header_above(c(&quot; “,”Group 1&quot; = 2, “Group 2” = 2, “Group 3” = 2)).</p>
-<pre class="r"><code>kable(dt) %&gt;%
+<pre class="r"><code>kable(dt, &quot;html&quot;) %&gt;%
   kable_styling(&quot;striped&quot;) %&gt;%
   add_header_above(c(&quot; &quot; = 1, &quot;Group 1&quot; = 2, &quot;Group 2&quot; = 2, &quot;Group 3&quot; = 2))</code></pre>
 <table class="table table-striped" style="margin-left: auto; margin-right: auto;">
@@ -1967,7 +1968,7 @@
 </tbody>
 </table>
 <p>In fact, if you want to add another row of header on top, please feel free to do so.</p>
-<pre class="r"><code>kable(dt) %&gt;%
+<pre class="r"><code>kable(dt, &quot;html&quot;) %&gt;%
   kable_styling(c(&quot;striped&quot;, &quot;bordered&quot;)) %&gt;%
   add_header_above(c(&quot; &quot;, &quot;Group 1&quot; = 2, &quot;Group 2&quot; = 2, &quot;Group 3&quot; = 2)) %&gt;%
   add_header_above(c(&quot; &quot;, &quot;Group 4&quot; = 4, &quot;Group 5&quot; = 2)) %&gt;%
@@ -2161,7 +2162,7 @@
 <div id="group-rows-via-labeling" class="section level2">
 <h2>Group rows via labeling</h2>
 <p>Sometimes we want a few rows of the table being grouped together. They might be items under the same topic (e.g., animals in one species) or just different data groups for a categorical variable (e.g., age &lt; 40, age &gt; 40). With the new function <code>group_rows()</code> in <code>kableExtra</code>, this kind of task can be completed in one line. Please see the example below. Note that when you count for the start/end rows of the group, you don’t need to count for the header rows nor other group label rows. You only need to think about the row numbers in the “original R dataframe”.</p>
-<pre class="r"><code>kable(mtcars[1:10, 1:6], caption = &quot;Group Rows&quot;) %&gt;%
+<pre class="r"><code>kable(mtcars[1:10, 1:6], &quot;html&quot;, caption = &quot;Group Rows&quot;) %&gt;%
   kable_styling(&quot;striped&quot;, full_width = F) %&gt;%
   group_rows(&quot;Group 1&quot;, 4, 7) %&gt;%
   group_rows(&quot;Group 2&quot;, 8, 10)</code></pre>
@@ -2437,7 +2438,7 @@
 </tbody>
 </table>
 <p>For advanced users, you can even define your own css for the group labeling.</p>
-<pre class="r"><code>kable(dt) %&gt;%
+<pre class="r"><code>kable(dt, &quot;html&quot;) %&gt;%
   kable_styling(&quot;striped&quot;, full_width = F) %&gt;%
   group_rows(&quot;Group 1&quot;, 3, 5, label_row_css = &quot;background-color: #666; color: #fff;&quot;)</code></pre>
 <table class="table table-striped" style="width: auto !important; margin-left: auto; margin-right: auto;">
@@ -2592,7 +2593,7 @@
 <div id="row-indentation" class="section level2">
 <h2>Row indentation</h2>
 <p>Unlike <code>group_rows()</code>, which will insert a labeling row, sometimes we want to list a few sub groups under a total one. In that case, <code>add_indent()</code> is probably more apporiate. For advanced users, you can even define your own css for the group labeling.</p>
-<pre class="r"><code>kable(dt) %&gt;%
+<pre class="r"><code>kable(dt, &quot;html&quot;) %&gt;%
   kable_styling(&quot;striped&quot;, full_width = F) %&gt;%
   add_indent(c(1, 3, 5))</code></pre>
 <table class="table table-striped" style="width: auto !important; margin-left: auto; margin-right: auto;">
@@ -2779,7 +2780,7 @@
 1
 </td>
 <td style="text-align:center;">
-0
+1
 </td>
 </tr>
 <tr>
@@ -2787,7 +2788,7 @@
 2
 </td>
 <td style="text-align:center;">
-0
+1
 </td>
 </tr>
 <tr>
@@ -2811,7 +2812,7 @@
 5
 </td>
 <td style="text-align:center;">
-1
+0
 </td>
 </tr>
 <tr>
@@ -2819,7 +2820,7 @@
 6
 </td>
 <td style="text-align:center;">
-1
+0
 </td>
 </tr>
 <tr>
@@ -2868,7 +2869,7 @@
 11
 </td>
 <td style="text-align:center;">
-1
+0
 </td>
 </tr>
 <tr>
@@ -2876,7 +2877,7 @@
 12
 </td>
 <td style="text-align:center;">
-0
+1
 </td>
 </tr>
 <tr>
@@ -2903,7 +2904,7 @@
 15
 </td>
 <td style="text-align:center;">
-1
+0
 </td>
 </tr>
 </tbody>
@@ -2917,7 +2918,7 @@
 <p>You can also use <code>add_footnote()</code> function from this package. You will need to supply a character vector with each element as one footnote. You may select from <code>number</code>, <code>alphabet</code> and <code>symbol</code> for different types of notations. Example are listed below.</p>
 <div id="alphabet" class="section level3">
 <h3>Alphabet</h3>
-<pre class="r"><code>kable(dt) %&gt;%
+<pre class="r"><code>kable(dt, &quot;html&quot;) %&gt;%
   kable_styling(&quot;striped&quot;) %&gt;%
   add_footnote(c(&quot;Footnote 1&quot;, &quot;Have a good day.&quot;), notation = &quot;alphabet&quot;)</code></pre>
 <table class="table table-striped" style="margin-left: auto; margin-right: auto;">
@@ -3078,7 +3079,7 @@
 </div>
 <div id="number" class="section level3">
 <h3>Number</h3>
-<pre class="r"><code>kable(dt) %&gt;%
+<pre class="r"><code>kable(dt, &quot;html&quot;) %&gt;%
   kable_styling(&quot;striped&quot;) %&gt;%
   add_footnote(c(&quot;Footnote 1&quot;, &quot;Have a good day.&quot;), notation = &quot;number&quot;)</code></pre>
 <table class="table table-striped" style="margin-left: auto; margin-right: auto;">
@@ -3239,7 +3240,7 @@
 </div>
 <div id="symbol" class="section level3">
 <h3>Symbol</h3>
-<pre class="r"><code>kable(dt) %&gt;%
+<pre class="r"><code>kable(dt, &quot;html&quot;) %&gt;%
   kable_styling(&quot;striped&quot;) %&gt;%
   add_footnote(c(&quot;Footnote 1&quot;, &quot;Footnote 2&quot;, &quot;Footnote 3&quot;), notation = &quot;symbol&quot;)</code></pre>
 <table class="table table-striped" style="margin-left: auto; margin-right: auto;">
@@ -3407,7 +3408,7 @@
 <div id="in-table-markers" class="section level2">
 <h2>In-table markers</h2>
 <p>By design, <code>add_footnote()</code> will transform any <code>[note]</code> to in-table footnote markers.</p>
-<pre class="r"><code>kable(dt, caption = &quot;Demo Table[note]&quot;) %&gt;%
+<pre class="r"><code>kable(dt, &quot;html&quot;, caption = &quot;Demo Table[note]&quot;) %&gt;%
   kable_styling(&quot;striped&quot;) %&gt;%
   add_header_above(c(&quot; &quot;, &quot;Group 1[note]&quot; = 3, &quot;Group 2[note]&quot; = 3)) %&gt;%
   add_footnote(c(&quot;This table is from mtcars&quot;, 
@@ -3599,7 +3600,7 @@
 <h2>Scroll box</h2>
 <p>If you have a huge table and you don’t want to reduce the font size to unreadable, you may want to put your HTML table in a scroll box, of which users can pick the part they like to read. Note that scroll box isn’t printer friendly, so be aware of that when you use this feature.</p>
 <p>When you use <code>scroll_box</code>, you can specify either <code>height</code> or <code>width</code>. When you specify <code>height</code>, you will get a vertically scrollable box and vice versa. If you specify both, you will get a two-way scrollable box.</p>
-<pre class="r"><code>kable(cbind(mtcars, mtcars)) %&gt;%
+<pre class="r"><code>kable(cbind(mtcars, mtcars), &quot;html&quot;) %&gt;%
   kable_styling() %&gt;%
   scroll_box(width = &quot;500px&quot;, height = &quot;200px&quot;)</code></pre>
 <div style="border: 1px solid #ddd; padding: 5px; overflow-y: scroll; height:200px; overflow-x: scroll; width:500px; ">
diff --git a/docs/awesome_table_in_pdf.Rmd b/docs/awesome_table_in_pdf.Rmd
index e0d7e77..9a55b87 100644
--- a/docs/awesome_table_in_pdf.Rmd
+++ b/docs/awesome_table_in_pdf.Rmd
@@ -108,12 +108,14 @@
 ```
 
 ### Hold position
-If you provide a table caption in `kable()`, it will put your LaTeX tabular in a `table` environment, unless you are using `longtable`. A `table` environment will automatically find the best place (it thinks) to put your table. However, in many cases, you do want your table to appear in a position you want it to be. In this case, you can use this `hold_position` options here.
+If you provide a table caption in `kable()`, it will put your LaTeX tabular in a `table` environment, unless you are using `longtable`. A `table` environment will automatically find the best place (it thinks) to put your table. However, in many cases, you do want your table to appear in a position you want it to be. In this case, you can use this `hold_position` options here. 
 ```{r}
 kable(dt, format = "latex", caption = "Demo table", booktabs = T) %>%
   kable_styling(latex_options = c("striped", "hold_position"))
 ```
 
+If you find `hold_position` is not powerful enough to literally PIN your table in the exact position, you may want to use `HOLD_position`, which is a more powerful version of this feature. For those who are familar with LaTeX, `hold_position` uses `[!h]` and `HOLD_position` uses `[H]` and the `float` package.
+
 ### Scale down
 When you have a wide table that will normally go out of the page and you want to scale down the table to fit the page, you can use the `scale_down` option here. Note that, if your table is too small, it will also scale up your table. It was named in this way only because scaling up isn't very useful in most cases. 
 ```{r}
@@ -137,10 +139,11 @@
 
 
 ## Full width?
-If you have a small table and you want it to spread wide on the page, you can try the `full_width` option. Unlike `scale_down`, it won't change your font size. Note that, if you use `full_width` in LaTeX, you will loss your in-cell text alignment settings and everything will be left-aligned. 
+If you have a small table and you want it to spread wide on the page, you can try the `full_width` option. Unlike `scale_down`, it won't change your font size. You can use `column_spec`, which will be explained later, together with `full_width` to achieve the best result.
 ```{r}
 kable(dt, format = "latex", booktabs = T) %>%
-  kable_styling(full_width = T)
+  kable_styling(full_width = T) %>%
+  column_spec(1, width = "8cm")
 ```
 
 ## Position
@@ -192,7 +195,7 @@
 kable(dt, format = "latex", booktabs = T) %>%
   kable_styling("striped", full_width = F) %>%
   column_spec(7, border_left = T, bold = T) %>%
-  row_spec(5, bold = T, color = "white", background = "black")
+  row_spec(3:5, bold = T, color = "white", background = "black")
 ```
 
 # Grouped Columns / Rows
@@ -228,6 +231,14 @@
   group_rows("Group 1", 4, 5, latex_gap_space = "2em")
 ```
 
+If you prefer to build multiple groups in one step, you can use the short-hand `index` option. Basically, you can use it in the same way as you use `add_header_above`. However, since `group_row` only support one layer of grouping, you can't add multiple layers of grouping header as you can do in `add_header_above`. 
+```{r, eval=FALSE}
+kable(mtcars[1:10, 1:6], format = "latex", caption = "Group Rows", booktabs = T) %>%
+  kable_styling() %>%
+  group_rows(index=c(" " = 3, "Group 1" = 4, "Group 2" = 3))
+# Not evaluated. The code above should have the same result as the first example in this section.
+```
+
 ## Row indentation
 Unlike `group_rows()`, which will insert a labeling row, sometimes we want to list a few sub groups under a total one. In that case, `add_indent()` is probably more apporiate. 
 For advanced users, you can even define your own css for the group labeling.
@@ -237,7 +248,7 @@
 ```
 
 ## Group rows via multi-row cell
-Function `group_rows` is great for showing simple structural information on rows but sometimes people may need to show structural information with multiple layers. When it happens, you may consider to use `collapse_rows` instead, which will put repeating cells in columns into multi-row cells. 
+Function `group_rows` is great for showing simple structural information on rows but sometimes people may need to show structural information with multiple layers. When it happens, you may consider to use `collapse_rows` instead, which will put repeating cells in columns into multi-row cells. If you even need to specify column/row format, use `column_spec` & `row_spec` before you pipe it into `collapse_rows`.
 
 ```{r}
 collapse_rows_dt <- data.frame(C1 = c(rep("a", 10), rep("b", 5)),
diff --git a/docs/awesome_table_in_pdf.pdf b/docs/awesome_table_in_pdf.pdf
index 2796962..79c240e 100644
--- a/docs/awesome_table_in_pdf.pdf
+++ b/docs/awesome_table_in_pdf.pdf
Binary files differ