diff --git a/docz/docs/08-api/07-utilities/05-csv.md b/docz/docs/08-api/07-utilities/05-csv.md
index 78c92bb..e31f1dc 100644
--- a/docz/docs/08-api/07-utilities/05-csv.md
+++ b/docz/docs/08-api/07-utilities/05-csv.md
@@ -61,7 +61,7 @@ produces CSV output.  The function takes an options argument:
 |`dateNF`      |  FMT 14  | Use specified date format in string output         |
 |`strip`       |  false   | Remove trailing field separators in each record ** |
 |`blankrows`   |  true    | Include blank lines in the CSV output              |
-|`skipHidden`  |  false   | Skips hidden rows/columns in the CSV output        |
+|`skipHidden`  | `false`  | [Skip hidden data](#hidden-rows-and-columns)       |
 |`forceQuotes` |  false   | Force quotes around fields                         |
 
 - `strip` will remove trailing commas from each line under default `FS/RS`
@@ -123,3 +123,52 @@ UTF-16 BOM will be added. If encoding support is not available, the output will
 be encoded as a standard `string`.
 
 `XLSX.utils.sheet_to_txt` takes the same arguments as `sheet_to_csv`.
+
+### Notes
+
+#### Hidden Rows and Columns
+
+By default, all rows and columns are rendered. The `skipHidden` option instructs
+the text processor to skip hidden rows and columns.
+
+The worksheet [`!rows` array](/docs/csf/features/rowprops) stores row settings.
+The [`!cols` array](/docs/csf/features/colprops) stores column settings.
+
+:::info pass
+
+By default, the `read` and `readFile` methods do not save row / column settings.
+[The `cellStyles` option must be set](/docs/api/parse-options#parsing-options).
+
+:::
+
+The following demo shows the effect of `skipHidden`. Rows 2 and 5 and columns F
+and G are marked as hidden. The hidden rows and columns are rendered by default
+but omitted when the `skipHidden` option is set to `true`.
+
+```jsx live
+function SheetJSCSVHiddenRows() {
+  var ws = XLSX.utils.aoa_to_sheet([
+    ["S", "h", "e", "e", "t", "J", "S", "Hidden (row)"],
+    [  1,   2,    ,    ,   5,   6,   7, true],
+    [  2,   3,    ,    ,   6,   7,   8, false],
+    [  3,   4,    ,    ,   7,   8,   9, false],
+    [  4,   5,   6,   7,   8,   9,   0, true],
+    [  0,   0,   0,   0,   0,   1,   1, false, "Hidden (col)"]
+  ]);
+
+  ws["!rows"] = [];
+  ws["!rows"][1] = { hidden: true, hpx: 16 }; // hide row 2
+  ws["!rows"][4] = { hidden: true, hpx: 16 }; // hide row 5
+
+  ws["!cols"] = [];
+  ws["!cols"][5] = { wch: 8, hidden: true }; // hide column F
+  ws["!cols"][6] = { wch: 8, hidden: true }; // hide column G
+
+  return ( <pre>
+    <b>Worksheet data (as HTML)</b>
+    <div dangerouslySetInnerHTML={{__html: XLSX.utils.sheet_to_html(ws)}}/>
+    <b>XLSX.utils.sheet_to_csv(ws, {'{'} skipHidden: true {'}'})</b><br/>
+    {XLSX.utils.sheet_to_csv(ws, { skipHidden: true })}<br/>
+  </pre> );
+}
+```
diff --git a/docz/docs/12-constellation/02-frac.md b/docz/docs/12-constellation/02-frac.md
index 7fe0a18..1f7afe8 100644
--- a/docz/docs/12-constellation/02-frac.md
+++ b/docz/docs/12-constellation/02-frac.md
@@ -27,6 +27,8 @@ function SheetJSFrac() {
   const [val, setVal] = React.useState(0.6994);
   const [text, setText] = React.useState("");
 
+  if(typeof frac == "undefined") return ( <b>ERROR: Reload this page</b> );
+
   const fmt = arr => `${(""+arr[1]).padStart(3)} / ${(""+arr[2]).padEnd(3)}`;
   React.useEffect(() => {
     if(typeof frac == "undefined") return setText("ERROR: Reload this page!");
@@ -93,7 +95,7 @@ processing involving fractions and numeric data.
 Both functions accept three arguments:
 
 ```js
-var fract_mediant  = frac(value, denominator, mixed);
+var frac_mediant   = frac(value, denominator, mixed);
 var frac_cont = frac.cont(value, denominator, mixed);
 ```