diff --git a/src/PhpSpreadsheet/IOFactory.php b/src/PhpSpreadsheet/IOFactory.php
index e437a2206..e7e725841 100644
--- a/src/PhpSpreadsheet/IOFactory.php
+++ b/src/PhpSpreadsheet/IOFactory.php
@@ -88,7 +88,9 @@ abstract class IOFactory
      * @param string $filename The name of the spreadsheet file
      * @param int $flags the optional second parameter flags may be used to identify specific elements
      *                       that should be loaded, but which won't be loaded by default, using these values:
-     *                            IReader::LOAD_WITH_CHARTS - Include any charts that are defined in the loaded file
+     *                            IReader::LOAD_WITH_CHARTS - Include any charts that are defined in the loaded file.
+     *                            IReader::READ_DATA_ONLY - Read cell values only, not formatting or merge structure.
+     *                            IReader::IGNORE_EMPTY_CELLS - Don't load empty cells into the model.
      * @param string[] $readers An array of Readers to use to identify the file type. By default, load() will try
      *                             all possible Readers until it finds a match; but this allows you to pass in a
      *                             list of Readers so it will only try the subset that you specify here.
diff --git a/src/PhpSpreadsheet/Reader/IReader.php b/src/PhpSpreadsheet/Reader/IReader.php
index 821ebe0ab..97afe3cb2 100644
--- a/src/PhpSpreadsheet/Reader/IReader.php
+++ b/src/PhpSpreadsheet/Reader/IReader.php
@@ -23,7 +23,8 @@ interface IReader
 
     /**
      * Read data only?
-     *        If this is true, then the Reader will only read data values for cells, it will not read any formatting information.
+     *        If this is true, then the Reader will only read data values for cells, it will not read any formatting
+     *           or structural information (like merges).
      *        If false (the default) it will read data and formatting.
      *
      * @return bool
@@ -32,7 +33,8 @@ interface IReader
 
     /**
      * Set read data only
-     *        Set to true, to advise the Reader only to read data values for cells, and to ignore any formatting information.
+     *        Set to true, to advise the Reader only to read data values for cells, and to ignore any formatting
+     *            or structural information (like merges).
      *        Set to false (the default) to advise the Reader to read both data and formatting for cells.
      *
      * @param bool $readDataOnly
@@ -63,9 +65,9 @@ interface IReader
 
     /**
      * Read charts in workbook?
-     *        If this is true, then the Reader will include any charts that exist in the workbook.
-     *      Note that a ReadDataOnly value of false overrides, and charts won't be read regardless of the IncludeCharts value.
-     *        If false (the default) it will ignore any charts defined in the workbook file.
+     *      If this is true, then the Reader will include any charts that exist in the workbook.
+     *         Note that a ReadDataOnly value of false overrides, and charts won't be read regardless of the IncludeCharts value.
+     *      If false (the default) it will ignore any charts defined in the workbook file.
      *
      * @return bool
      */
@@ -73,9 +75,9 @@ interface IReader
 
     /**
      * Set read charts in workbook
-     *        Set to true, to advise the Reader to include any charts that exist in the workbook.
-     *      Note that a ReadDataOnly value of false overrides, and charts won't be read regardless of the IncludeCharts value.
-     *        Set to false (the default) to discard charts.
+     *     Set to true, to advise the Reader to include any charts that exist in the workbook.
+     *         Note that a ReadDataOnly value of false overrides, and charts won't be read regardless of the IncludeCharts value.
+     *     Set to false (the default) to discard charts.
      *
      * @param bool $includeCharts
      *