diff --git a/README.md b/README.md
index cba427e..481d20f 100644
--- a/README.md
+++ b/README.md
@@ -3257,12 +3257,12 @@ c  6  7
 +------------------------+---------------+------------+------------+--------------------------+
 |                        |    'outer'    |   'inner'  |   'left'   |       Description        |
 +------------------------+---------------+------------+------------+--------------------------+
-| l.merge(r, on='y',     |    x   y   z  | x   y   z  | x   y   z  | Joins/merges on column.  |
-|            how=…)      | 0  1   2   .  | 3   4   5  | 1   2   .  | Also accepts left_on and |
-|                        | 1  3   4   5  |            | 3   4   5  | right_on parameters.     |
+| l.merge(r, on='y',     |    x   y   z  | x   y   z  | x   y   z  | Merges on column if 'on' |
+|            how=…)      | 0  1   2   .  | 3   4   5  | 1   2   .  | or 'left/right_on' are   |
+|                        | 1  3   4   5  |            | 3   4   5  | set, else on shared cols.|
 |                        | 2  .   6   7  |            |            | Uses 'inner' by default. |
 +------------------------+---------------+------------+------------+--------------------------+
-| l.join(r, lsuffix='l', |    x yl yr  z |            | x yl yr  z | Joins/merges on row keys.|
+| l.join(r, lsuffix='l', |    x yl yr  z |            | x yl yr  z | Merges on row keys.      |
 |           rsuffix='r', | a  1  2  .  . | x yl yr  z | 1  2  .  . | Uses 'left' by default.  |
 |           how=…)       | b  3  4  4  5 | 3  4  4  5 | 3  4  4  5 | If r is a Series, it is  |
 |                        | c  .  .  6  7 |            |            | treated as a column.     |
@@ -3270,8 +3270,8 @@ c  6  7
 | pd.concat([l, r],      |    x   y   z  |     y      |            | Adds rows at the bottom. |
 |           axis=0,      | a  1   2   .  |     2      |            | Uses 'outer' by default. |
 |           join=…)      | b  3   4   .  |     4      |            | A Series is treated as a |
-|                        | b  .   4   5  |     4      |            | column. Use l.append(sr) |
-|                        | c  .   6   7  |     6      |            | to add a row instead.    |
+|                        | b  .   4   5  |     4      |            | column. To add a row use |
+|                        | c  .   6   7  |     6      |            | pd.concat([l, DF([sr])]).|
 +------------------------+---------------+------------+------------+--------------------------+
 | pd.concat([l, r],      |    x  y  y  z |            |            | Adds columns at the      |
 |           axis=1,      | a  1  2  .  . | x  y  y  z |            | right end. Uses 'outer'  |
diff --git a/index.html b/index.html
index 5298734..9718977 100644
--- a/index.html
+++ b/index.html
@@ -2654,12 +2654,12 @@ c  <span class="hljs-number">6</span>  <span class="hljs-number">7</span>
 <pre><code class="python hljs">┏━━━━━━━━━━━━━━━━━━━━━━━━┯━━━━━━━━━━━━━━━┯━━━━━━━━━━━━┯━━━━━━━━━━━━┯━━━━━━━━━━━━━━━━━━━━━━━━━━┓
 ┃                        │    <span class="hljs-string">'outer'</span>    │   <span class="hljs-string">'inner'</span>  │   <span class="hljs-string">'left'</span>   │       Description        ┃
 ┠────────────────────────┼───────────────┼────────────┼────────────┼──────────────────────────┨
-┃ l.merge(r, on=<span class="hljs-string">'y'</span>,     │    x   y   z  │ x   y   z  │ x   y   z  │ Joins/merges on column.  ┃
-┃            how=…)      │ <span class="hljs-number">0</span>  <span class="hljs-number">1</span>   <span class="hljs-number">2</span>   .  │ <span class="hljs-number">3</span>   <span class="hljs-number">4</span>   <span class="hljs-number">5</span>  │ <span class="hljs-number">1</span>   <span class="hljs-number">2</span>   .  │ Also accepts left_on and ┃
-┃                        │ <span class="hljs-number">1</span>  <span class="hljs-number">3</span>   <span class="hljs-number">4</span>   <span class="hljs-number">5</span>  │            │ <span class="hljs-number">3</span>   <span class="hljs-number">4</span>   <span class="hljs-number">5</span>  │ right_on parameters.     ┃
+┃ l.merge(r, on=<span class="hljs-string">'y'</span>,     │    x   y   z  │ x   y   z  │ x   y   z  │ Merges on column if <span class="hljs-string">'on'</span> ┃
+┃            how=…)      │ <span class="hljs-number">0</span>  <span class="hljs-number">1</span>   <span class="hljs-number">2</span>   .  │ <span class="hljs-number">3</span>   <span class="hljs-number">4</span>   <span class="hljs-number">5</span>  │ <span class="hljs-number">1</span>   <span class="hljs-number">2</span>   .  │ or <span class="hljs-string">'left/right_on'</span> are   ┃
+┃                        │ <span class="hljs-number">1</span>  <span class="hljs-number">3</span>   <span class="hljs-number">4</span>   <span class="hljs-number">5</span>  │            │ <span class="hljs-number">3</span>   <span class="hljs-number">4</span>   <span class="hljs-number">5</span>  │ set, else on shared cols.┃
 ┃                        │ <span class="hljs-number">2</span>  .   <span class="hljs-number">6</span>   <span class="hljs-number">7</span>  │            │            │ Uses <span class="hljs-string">'inner'</span> by default. ┃
 ┠────────────────────────┼───────────────┼────────────┼────────────┼──────────────────────────┨
-┃ l.join(r, lsuffix=<span class="hljs-string">'l'</span>, │    x yl yr  z │            │ x yl yr  z │ Joins/merges on row keys.┃
+┃ l.join(r, lsuffix=<span class="hljs-string">'l'</span>, │    x yl yr  z │            │ x yl yr  z │ Merges on row keys.      ┃
 ┃           rsuffix=<span class="hljs-string">'r'</span>, │ a  <span class="hljs-number">1</span>  <span class="hljs-number">2</span>  .  . │ x yl yr  z │ <span class="hljs-number">1</span>  <span class="hljs-number">2</span>  .  . │ Uses <span class="hljs-string">'left'</span> by default.  ┃
 ┃           how=…)       │ b  <span class="hljs-number">3</span>  <span class="hljs-number">4</span>  <span class="hljs-number">4</span>  <span class="hljs-number">5</span> │ <span class="hljs-number">3</span>  <span class="hljs-number">4</span>  <span class="hljs-number">4</span>  <span class="hljs-number">5</span> │ <span class="hljs-number">3</span>  <span class="hljs-number">4</span>  <span class="hljs-number">4</span>  <span class="hljs-number">5</span> │ If r is a Series, it is  ┃
 ┃                        │ c  .  .  <span class="hljs-number">6</span>  <span class="hljs-number">7</span> │            │            │ treated as a column.     ┃
@@ -2667,8 +2667,8 @@ c  <span class="hljs-number">6</span>  <span class="hljs-number">7</span>
 ┃ pd.concat([l, r],      │    x   y   z  │     y      │            │ Adds rows at the bottom. ┃
 ┃           axis=<span class="hljs-number">0</span>,      │ a  <span class="hljs-number">1</span>   <span class="hljs-number">2</span>   .  │     <span class="hljs-number">2</span>      │            │ Uses <span class="hljs-string">'outer'</span> by default. ┃
 ┃           join=…)      │ b  <span class="hljs-number">3</span>   <span class="hljs-number">4</span>   .  │     <span class="hljs-number">4</span>      │            │ A Series is treated as a ┃
-┃                        │ b  .   <span class="hljs-number">4</span>   <span class="hljs-number">5</span>  │     <span class="hljs-number">4</span>      │            │ column. Use l.append(sr) ┃
-┃                        │ c  .   <span class="hljs-number">6</span>   <span class="hljs-number">7</span>  │     <span class="hljs-number">6</span>      │            │ to add a row instead.    ┃
+┃                        │ b  .   <span class="hljs-number">4</span>   <span class="hljs-number">5</span>  │     <span class="hljs-number">4</span>      │            │ column. To add a row use ┃
+┃                        │ c  .   <span class="hljs-number">6</span>   <span class="hljs-number">7</span>  │     <span class="hljs-number">6</span>      │            │ pd.concat([l, DF([sr])]).┃
 ┠────────────────────────┼───────────────┼────────────┼────────────┼──────────────────────────┨
 ┃ pd.concat([l, r],      │    x  y  y  z │            │            │ Adds columns at the      ┃
 ┃           axis=<span class="hljs-number">1</span>,      │ a  <span class="hljs-number">1</span>  <span class="hljs-number">2</span>  .  . │ x  y  y  z │            │ right end. Uses <span class="hljs-string">'outer'</span>  ┃
@@ -2725,7 +2725,7 @@ plt.show()                                     <span class="hljs-comment"># Disp
 &lt;DF&gt; = pd.read_clipboard()                     <span class="hljs-comment"># Reads a copied table from the clipboard.</span>
 </code></pre>
 <pre><code class="python language-python hljs">&lt;dict&gt; = &lt;DF&gt;.to_dict([<span class="hljs-string">'d/l/s/…'</span>])             <span class="hljs-comment"># Returns columns as dicts, lists or series.</span>
-&lt;str&gt;  = &lt;DF&gt;.to_json/html/csv([&lt;path&gt;])       <span class="hljs-comment"># Also &lt;DF&gt;.to_markdown/latex([&lt;path&gt;]).</span>
+&lt;str&gt;  = &lt;DF&gt;.to_json/html/csv([&lt;path&gt;])       <span class="hljs-comment"># Also to_markdown/latex([&lt;path&gt;]).</span>
 &lt;DF&gt;.to_pickle/excel(&lt;path&gt;)                   <span class="hljs-comment"># Run `$ pip3 install openpyxl` for xlsx files.</span>
 &lt;DF&gt;.to_sql(<span class="hljs-string">'&lt;table_name&gt;'</span>, &lt;connection&gt;)      <span class="hljs-comment"># Accepts SQLite3 or SQLAlchemy connection.</span>
 </code></pre>
diff --git a/parse.js b/parse.js
index 51e21ce..9dfc007 100755
--- a/parse.js
+++ b/parse.js
@@ -511,12 +511,12 @@ const DIAGRAM_15_B =
   "┏━━━━━━━━━━━━━━━━━━━━━━━━┯━━━━━━━━━━━━━━━┯━━━━━━━━━━━━┯━━━━━━━━━━━━┯━━━━━━━━━━━━━━━━━━━━━━━━━━┓\n" +
   "┃                        │    'outer'    │   'inner'  │   'left'   │       Description        ┃\n" +
   "┠────────────────────────┼───────────────┼────────────┼────────────┼──────────────────────────┨\n" +
-  "┃ l.merge(r, on='y',     │    x   y   z  │ x   y   z  │ x   y   z  │ Joins/merges on column.  ┃\n" +
-  "┃            how=…)      │ 0  1   2   .  │ 3   4   5  │ 1   2   .  │ Also accepts left_on and ┃\n" +
-  "┃                        │ 1  3   4   5  │            │ 3   4   5  │ right_on parameters.     ┃\n" +
+  "┃ l.merge(r, on='y',     │    x   y   z  │ x   y   z  │ x   y   z  │ Merges on column if 'on' ┃\n" +
+  "┃            how=…)      │ 0  1   2   .  │ 3   4   5  │ 1   2   .  │ or 'left/right_on' are   ┃\n" +
+  "┃                        │ 1  3   4   5  │            │ 3   4   5  │ set, else on shared cols.┃\n" +
   "┃                        │ 2  .   6   7  │            │            │ Uses 'inner' by default. ┃\n" +
   "┠────────────────────────┼───────────────┼────────────┼────────────┼──────────────────────────┨\n" +
-  "┃ l.join(r, lsuffix='l', │    x yl yr  z │            │ x yl yr  z │ Joins/merges on row keys.┃\n" +
+  "┃ l.join(r, lsuffix='l', │    x yl yr  z │            │ x yl yr  z │ Merges on row keys.      ┃\n" +
   "┃           rsuffix='r', │ a  1  2  .  . │ x yl yr  z │ 1  2  .  . │ Uses 'left' by default.  ┃\n" +
   "┃           how=…)       │ b  3  4  4  5 │ 3  4  4  5 │ 3  4  4  5 │ If r is a Series, it is  ┃\n" +
   "┃                        │ c  .  .  6  7 │            │            │ treated as a column.     ┃\n" +
@@ -524,8 +524,8 @@ const DIAGRAM_15_B =
   "┃ pd.concat([l, r],      │    x   y   z  │     y      │            │ Adds rows at the bottom. ┃\n" +
   "┃           axis=0,      │ a  1   2   .  │     2      │            │ Uses 'outer' by default. ┃\n" +
   "┃           join=…)      │ b  3   4   .  │     4      │            │ A Series is treated as a ┃\n" +
-  "┃                        │ b  .   4   5  │     4      │            │ column. Use l.append(sr) ┃\n" +
-  "┃                        │ c  .   6   7  │     6      │            │ to add a row instead.    ┃\n" +
+  "┃                        │ b  .   4   5  │     4      │            │ column. To add a row use ┃\n" +
+  "┃                        │ c  .   6   7  │     6      │            │ pd.concat([l, DF([sr])]).┃\n" +
   "┠────────────────────────┼───────────────┼────────────┼────────────┼──────────────────────────┨\n" +
   "┃ pd.concat([l, r],      │    x  y  y  z │            │            │ Adds columns at the      ┃\n" +
   "┃           axis=1,      │ a  1  2  .  . │ x  y  y  z │            │ right end. Uses 'outer'  ┃\n" +
@@ -798,6 +798,9 @@ function fixPandasDiagram() {
   $(`code:contains(${diagram_15})`).find(".hljs-keyword:contains(and)").after("and");
   $(`code:contains(${diagram_15})`).find(".hljs-keyword:contains(as)").after("as");
   $(`code:contains(${diagram_15})`).find(".hljs-keyword:contains(is)").after("is");
+  $(`code:contains(${diagram_15})`).find(".hljs-keyword:contains(if)").after("if");
+  $(`code:contains(${diagram_15})`).find(".hljs-keyword:contains(or)").after("or");
+  $(`code:contains(${diagram_15})`).find(".hljs-keyword:contains(else)").after("else");
   $(`code:contains(${diagram_15})`).find(".hljs-keyword").remove();
 }