diff --git a/src/Spout/Common/Exception/BadUsageException.php b/src/Spout/Common/Exception/BadUsageException.php
deleted file mode 100644
index 716dfc3..0000000
--- a/src/Spout/Common/Exception/BadUsageException.php
+++ /dev/null
@@ -1,12 +0,0 @@
-<?php
-
-namespace Box\Spout\Common\Exception;
-
-/**
- * Class BadUsageException
- *
- * @package Box\Spout\Common\Exception
- */
-class BadUsageException extends SpoutException
-{
-}
diff --git a/src/Spout/Common/Exception/EncodingConversionException.php b/src/Spout/Common/Exception/EncodingConversionException.php
index ff5e243..6dcc0a8 100644
--- a/src/Spout/Common/Exception/EncodingConversionException.php
+++ b/src/Spout/Common/Exception/EncodingConversionException.php
@@ -5,6 +5,7 @@ namespace Box\Spout\Common\Exception;
 /**
  * Class EncodingConversionException
  *
+ * @api
  * @package Box\Spout\Common\Exception
  */
 class EncodingConversionException extends SpoutException
diff --git a/src/Spout/Common/Exception/IOException.php b/src/Spout/Common/Exception/IOException.php
index 9c377a0..4307ca4 100644
--- a/src/Spout/Common/Exception/IOException.php
+++ b/src/Spout/Common/Exception/IOException.php
@@ -5,6 +5,7 @@ namespace Box\Spout\Common\Exception;
 /**
  * Class IOException
  *
+ * @api
  * @package Box\Spout\Common\Exception
  */
 class IOException extends SpoutException
diff --git a/src/Spout/Common/Exception/InvalidArgumentException.php b/src/Spout/Common/Exception/InvalidArgumentException.php
index bb88dd4..b1ec05f 100644
--- a/src/Spout/Common/Exception/InvalidArgumentException.php
+++ b/src/Spout/Common/Exception/InvalidArgumentException.php
@@ -5,6 +5,7 @@ namespace Box\Spout\Common\Exception;
 /**
  * Class InvalidArgumentException
  *
+ * @api
  * @package Box\Spout\Common\Exception
  */
 class InvalidArgumentException extends SpoutException
diff --git a/src/Spout/Common/Exception/SpoutException.php b/src/Spout/Common/Exception/SpoutException.php
index 7e937a6..aa762d7 100644
--- a/src/Spout/Common/Exception/SpoutException.php
+++ b/src/Spout/Common/Exception/SpoutException.php
@@ -6,6 +6,7 @@ namespace Box\Spout\Common\Exception;
  * Class SpoutException
  *
  * @package Box\Spout\Common\Exception
+ * @abstract
  */
 abstract class SpoutException extends \Exception
 {
diff --git a/src/Spout/Common/Exception/UnsupportedTypeException.php b/src/Spout/Common/Exception/UnsupportedTypeException.php
index 434da8f..65e8500 100644
--- a/src/Spout/Common/Exception/UnsupportedTypeException.php
+++ b/src/Spout/Common/Exception/UnsupportedTypeException.php
@@ -5,6 +5,7 @@ namespace Box\Spout\Common\Exception;
 /**
  * Class UnsupportedTypeException
  *
+ * @api
  * @package Box\Spout\Common\Exception
  */
 class UnsupportedTypeException extends SpoutException
diff --git a/src/Spout/Common/Type.php b/src/Spout/Common/Type.php
index 24c0718..5e9b75e 100644
--- a/src/Spout/Common/Type.php
+++ b/src/Spout/Common/Type.php
@@ -5,6 +5,8 @@ namespace Box\Spout\Common;
 /**
  * Class Type
  * This class references the supported types
+ *
+ * @api
  */
 abstract class Type
 {
diff --git a/src/Spout/Reader/AbstractReader.php b/src/Spout/Reader/AbstractReader.php
index e55bdec..ece60ca 100644
--- a/src/Spout/Reader/AbstractReader.php
+++ b/src/Spout/Reader/AbstractReader.php
@@ -55,6 +55,7 @@ abstract class AbstractReader implements ReaderInterface
      * Prepares the reader to read the given file. It also makes sure
      * that the file exists and is readable.
      *
+     * @api
      * @param  string $filePath Path of the file to be read
      * @return void
      * @throws \Box\Spout\Common\Exception\IOException If the file at the given path does not exist, is not readable or is corrupted
@@ -92,6 +93,7 @@ abstract class AbstractReader implements ReaderInterface
     /**
      * Returns an iterator to iterate over sheets.
      *
+     * @api
      * @return \Iterator To iterate over sheets
      * @throws \Box\Spout\Reader\Exception\ReaderNotOpenedException If called before opening the reader
      */
@@ -107,6 +109,7 @@ abstract class AbstractReader implements ReaderInterface
     /**
      * Closes the reader, preventing any additional reading
      *
+     * @api
      * @return void
      */
     public function close()
diff --git a/src/Spout/Reader/CSV/Sheet.php b/src/Spout/Reader/CSV/Sheet.php
index fd8d214..a417709 100644
--- a/src/Spout/Reader/CSV/Sheet.php
+++ b/src/Spout/Reader/CSV/Sheet.php
@@ -27,6 +27,7 @@ class Sheet implements SheetInterface
     }
 
     /**
+     * @api
      * @return RowIterator
      */
     public function getRowIterator()
diff --git a/src/Spout/Reader/Exception/IteratorNotRewindableException.php b/src/Spout/Reader/Exception/IteratorNotRewindableException.php
index 0277fa3..a030c12 100644
--- a/src/Spout/Reader/Exception/IteratorNotRewindableException.php
+++ b/src/Spout/Reader/Exception/IteratorNotRewindableException.php
@@ -5,6 +5,7 @@ namespace Box\Spout\Reader\Exception;
 /**
  * Class IteratorNotRewindableException
  *
+ * @api
  * @package Box\Spout\Reader\Exception
  */
 class IteratorNotRewindableException extends ReaderException
diff --git a/src/Spout/Reader/Exception/NoSheetsFoundException.php b/src/Spout/Reader/Exception/NoSheetsFoundException.php
index dfc4907..38d8772 100644
--- a/src/Spout/Reader/Exception/NoSheetsFoundException.php
+++ b/src/Spout/Reader/Exception/NoSheetsFoundException.php
@@ -5,6 +5,7 @@ namespace Box\Spout\Reader\Exception;
 /**
  * Class NoSheetsFoundException
  *
+ * @api
  * @package Box\Spout\Reader\Exception
  */
 class NoSheetsFoundException extends ReaderException
diff --git a/src/Spout/Reader/Exception/ReaderNotOpenedException.php b/src/Spout/Reader/Exception/ReaderNotOpenedException.php
index 5fb679d..8f94de3 100644
--- a/src/Spout/Reader/Exception/ReaderNotOpenedException.php
+++ b/src/Spout/Reader/Exception/ReaderNotOpenedException.php
@@ -5,6 +5,7 @@ namespace Box\Spout\Reader\Exception;
 /**
  * Class ReaderNotOpenedException
  *
+ * @api
  * @package Box\Spout\Reader\Exception
  */
 class ReaderNotOpenedException extends ReaderException
diff --git a/src/Spout/Reader/Exception/SharedStringNotFoundException.php b/src/Spout/Reader/Exception/SharedStringNotFoundException.php
index 32d1e6d..b494612 100644
--- a/src/Spout/Reader/Exception/SharedStringNotFoundException.php
+++ b/src/Spout/Reader/Exception/SharedStringNotFoundException.php
@@ -5,6 +5,7 @@ namespace Box\Spout\Reader\Exception;
 /**
  * Class SharedStringNotFoundException
  *
+ * @api
  * @package Box\Spout\Reader\Exception
  */
 class SharedStringNotFoundException extends ReaderException
diff --git a/src/Spout/Reader/ODS/Sheet.php b/src/Spout/Reader/ODS/Sheet.php
index c023182..012f635 100644
--- a/src/Spout/Reader/ODS/Sheet.php
+++ b/src/Spout/Reader/ODS/Sheet.php
@@ -38,6 +38,7 @@ class Sheet implements SheetInterface
     }
 
     /**
+     * @api
      * @return RowIterator
      */
     public function getRowIterator()
@@ -46,6 +47,7 @@ class Sheet implements SheetInterface
     }
 
     /**
+     * @api
      * @return int Index of the sheet, based on order of creation (zero-based)
      */
     public function getIndex()
@@ -54,6 +56,7 @@ class Sheet implements SheetInterface
     }
 
     /**
+     * @api
      * @return string Name of the sheet
      */
     public function getName()
diff --git a/src/Spout/Reader/ReaderFactory.php b/src/Spout/Reader/ReaderFactory.php
index 3a32094..93a52cb 100644
--- a/src/Spout/Reader/ReaderFactory.php
+++ b/src/Spout/Reader/ReaderFactory.php
@@ -18,6 +18,7 @@ class ReaderFactory
     /**
      * This creates an instance of the appropriate reader, given the type of the file to be read
      *
+     * @api
      * @param  string $readerType Type of the reader to instantiate
      * @return ReaderInterface
      * @throws \Box\Spout\Common\Exception\UnsupportedTypeException
diff --git a/src/Spout/Reader/XLSX/Sheet.php b/src/Spout/Reader/XLSX/Sheet.php
index ce88212..b0babf7 100644
--- a/src/Spout/Reader/XLSX/Sheet.php
+++ b/src/Spout/Reader/XLSX/Sheet.php
@@ -36,6 +36,7 @@ class Sheet implements SheetInterface
     }
 
     /**
+     * @api
      * @return RowIterator
      */
     public function getRowIterator()
@@ -44,6 +45,7 @@ class Sheet implements SheetInterface
     }
 
     /**
+     * @api
      * @return int Index of the sheet, based on order of creation (zero-based)
      */
     public function getIndex()
@@ -52,6 +54,7 @@ class Sheet implements SheetInterface
     }
 
     /**
+     * @api
      * @return string Name of the sheet
      */
     public function getName()
diff --git a/src/Spout/Writer/AbstractMultiSheetsWriter.php b/src/Spout/Writer/AbstractMultiSheetsWriter.php
index 8e1114d..d119660 100644
--- a/src/Spout/Writer/AbstractMultiSheetsWriter.php
+++ b/src/Spout/Writer/AbstractMultiSheetsWriter.php
@@ -24,6 +24,7 @@ abstract class AbstractMultiSheetsWriter extends AbstractWriter
      * Sets whether new sheets should be automatically created when the max rows limit per sheet is reached.
      * This must be set before opening the writer.
      *
+     * @api
      * @param bool $shouldCreateNewSheetsAutomatically Whether new sheets should be automatically created when the max rows limit per sheet is reached
      * @return AbstractMultiSheetsWriter
      * @throws \Box\Spout\Writer\Exception\WriterAlreadyOpenedException If the writer was already opened
@@ -39,6 +40,7 @@ abstract class AbstractMultiSheetsWriter extends AbstractWriter
     /**
      * Returns all the workbook's sheets
      *
+     * @api
      * @return Common\Sheet[] All the workbook's sheets
      * @throws \Box\Spout\Writer\Exception\WriterNotOpenedException If the writer has not been opened yet
      */
@@ -60,6 +62,7 @@ abstract class AbstractMultiSheetsWriter extends AbstractWriter
     /**
      * Creates a new sheet and make it the current sheet. The data will now be written to this sheet.
      *
+     * @api
      * @return Common\Sheet The created sheet
      * @throws \Box\Spout\Writer\Exception\WriterNotOpenedException If the writer has not been opened yet
      */
@@ -74,6 +77,7 @@ abstract class AbstractMultiSheetsWriter extends AbstractWriter
     /**
      * Returns the current sheet
      *
+     * @api
      * @return Common\Sheet The current sheet
      * @throws \Box\Spout\Writer\Exception\WriterNotOpenedException If the writer has not been opened yet
      */
@@ -87,6 +91,7 @@ abstract class AbstractMultiSheetsWriter extends AbstractWriter
      * Sets the given sheet as the current one. New data will be written to this sheet.
      * The writing will resume where it stopped (i.e. data won't be truncated).
      *
+     * @api
      * @param Common\Sheet $sheet The sheet to set as current
      * @return void
      * @throws \Box\Spout\Writer\Exception\WriterNotOpenedException If the writer has not been opened yet
diff --git a/src/Spout/Writer/AbstractWriter.php b/src/Spout/Writer/AbstractWriter.php
index 99c2232..fa8218f 100644
--- a/src/Spout/Writer/AbstractWriter.php
+++ b/src/Spout/Writer/AbstractWriter.php
@@ -85,6 +85,7 @@ abstract class AbstractWriter implements WriterInterface
      * Inits the writer and opens it to accept data.
      * By using this method, the data will be written to a file.
      *
+     * @api
      * @param  string $outputFilePath Path of the output file that will contain the data
      * @return AbstractWriter
      * @throws \Box\Spout\Common\Exception\IOException If the writer cannot be opened or if the given path is not writable
@@ -108,6 +109,7 @@ abstract class AbstractWriter implements WriterInterface
      *
      * @codeCoverageIgnore
      *
+     * @api
      * @param  string $outputFileName Name of the output file that will contain the data. If a path is passed in, only the file name will be kept
      * @return AbstractWriter
      * @throws \Box\Spout\Common\Exception\IOException If the writer cannot be opened
@@ -174,7 +176,7 @@ abstract class AbstractWriter implements WriterInterface
      * @param  array $dataRow Array containing data to be streamed.
      *                        If empty, no data is added (i.e. not even as a blank row)
      *                        Example: $dataRow = ['data1', 1234, null, '', 'data5', false];
-     *
+     * @api
      * @return AbstractWriter
      * @throws \Box\Spout\Writer\Exception\WriterNotOpenedException If this function is called before opening the writer
      * @throws \Box\Spout\Common\Exception\IOException If unable to write data
@@ -197,6 +199,7 @@ abstract class AbstractWriter implements WriterInterface
      * Write given data to the output and apply the given style.
      * @see addRow
      *
+     * @api
      * @param array $dataRow Array of array containing data to be streamed.
      * @param Style\Style $style Style to be applied to the row.
      * @return AbstractWriter
@@ -220,13 +223,13 @@ abstract class AbstractWriter implements WriterInterface
     /**
      * Write given data to the output. New data will be appended to end of stream.
      *
+     * @api
      * @param  array $dataRows Array of array containing data to be streamed.
      *                         If a row is empty, it won't be added (i.e. not even as a blank row)
      *                         Example: $dataRows = [
      *                             ['data11', 12, , '', 'data13'],
      *                             ['data21', 'data22', null, false],
      *                         ];
-     *
      * @return AbstractWriter
      * @throws \Box\Spout\Common\Exception\InvalidArgumentException If the input param is not valid
      * @throws \Box\Spout\Writer\Exception\WriterNotOpenedException If this function is called before opening the writer
@@ -251,6 +254,7 @@ abstract class AbstractWriter implements WriterInterface
      * Write given data to the output and apply the given style.
      * @see addRows
      *
+     * @api
      * @param array $dataRows Array of array containing data to be streamed.
      * @param Style\Style $style Style to be applied to the rows.
      * @return AbstractWriter
@@ -309,6 +313,7 @@ abstract class AbstractWriter implements WriterInterface
      * Closes the writer. This will close the streamer as well, preventing new data
      * to be written to the file.
      *
+     * @api
      * @return void
      */
     public function close()
diff --git a/src/Spout/Writer/CSV/Writer.php b/src/Spout/Writer/CSV/Writer.php
index 0ce4f39..e6ccc65 100644
--- a/src/Spout/Writer/CSV/Writer.php
+++ b/src/Spout/Writer/CSV/Writer.php
@@ -32,6 +32,7 @@ class Writer extends AbstractWriter
     /**
      * Sets the field delimiter for the CSV
      *
+     * @api
      * @param string $fieldDelimiter Character that delimits fields
      * @return Writer
      */
@@ -44,6 +45,7 @@ class Writer extends AbstractWriter
     /**
      * Sets the field enclosure for the CSV
      *
+     * @api
      * @param string $fieldEnclosure Character that enclose fields
      * @return Writer
      */
diff --git a/src/Spout/Writer/Common/Sheet.php b/src/Spout/Writer/Common/Sheet.php
index ba34d11..c46c876 100644
--- a/src/Spout/Writer/Common/Sheet.php
+++ b/src/Spout/Writer/Common/Sheet.php
@@ -44,6 +44,7 @@ class Sheet
     }
 
     /**
+     * @api
      * @return int Index of the sheet, based on order of creation (zero-based)
      */
     public function getIndex()
@@ -52,6 +53,7 @@ class Sheet
     }
 
     /**
+     * @api
      * @return string Name of the sheet
      */
     public function getName()
@@ -66,6 +68,7 @@ class Sheet
      *  - it should not contain these characters: \ / ? * : [ or ]
      *  - it should be unique
      *
+     * @api
      * @param string $name Name of the sheet
      * @return Sheet
      * @throws \Box\Spout\Writer\Exception\InvalidSheetNameException If the sheet's name is invalid.
diff --git a/src/Spout/Writer/Exception/InvalidColorException.php b/src/Spout/Writer/Exception/InvalidColorException.php
index b00dfa4..49b4a0d 100644
--- a/src/Spout/Writer/Exception/InvalidColorException.php
+++ b/src/Spout/Writer/Exception/InvalidColorException.php
@@ -5,6 +5,7 @@ namespace Box\Spout\Writer\Exception;
 /**
  * Class InvalidColorException
  *
+ * @api
  * @package Box\Spout\Writer\Exception
  */
 class InvalidColorException extends WriterException
diff --git a/src/Spout/Writer/Exception/InvalidSheetNameException.php b/src/Spout/Writer/Exception/InvalidSheetNameException.php
index 501b97b..ae0663e 100644
--- a/src/Spout/Writer/Exception/InvalidSheetNameException.php
+++ b/src/Spout/Writer/Exception/InvalidSheetNameException.php
@@ -5,6 +5,7 @@ namespace Box\Spout\Writer\Exception;
 /**
  * Class InvalidSheetNameException
  *
+ * @api
  * @package Box\Spout\Writer\Exception
  */
 class InvalidSheetNameException extends WriterException
diff --git a/src/Spout/Writer/Exception/SheetNotFoundException.php b/src/Spout/Writer/Exception/SheetNotFoundException.php
index c28ac9e..c0ded5a 100644
--- a/src/Spout/Writer/Exception/SheetNotFoundException.php
+++ b/src/Spout/Writer/Exception/SheetNotFoundException.php
@@ -5,6 +5,7 @@ namespace Box\Spout\Writer\Exception;
 /**
  * Class SheetNotFoundException
  *
+ * @api
  * @package Box\Spout\Writer\Exception
  */
 class SheetNotFoundException extends WriterException
diff --git a/src/Spout/Writer/Exception/WriterAlreadyOpenedException.php b/src/Spout/Writer/Exception/WriterAlreadyOpenedException.php
index f4c49a8..657d611 100644
--- a/src/Spout/Writer/Exception/WriterAlreadyOpenedException.php
+++ b/src/Spout/Writer/Exception/WriterAlreadyOpenedException.php
@@ -5,6 +5,7 @@ namespace Box\Spout\Writer\Exception;
 /**
  * Class WriterAlreadyOpenedException
  *
+ * @api
  * @package Box\Spout\Writer\Exception
  */
 class WriterAlreadyOpenedException extends WriterException
diff --git a/src/Spout/Writer/Exception/WriterNotOpenedException.php b/src/Spout/Writer/Exception/WriterNotOpenedException.php
index b2b8201..5b08477 100644
--- a/src/Spout/Writer/Exception/WriterNotOpenedException.php
+++ b/src/Spout/Writer/Exception/WriterNotOpenedException.php
@@ -5,6 +5,7 @@ namespace Box\Spout\Writer\Exception;
 /**
  * Class WriterNotOpenedException
  *
+ * @api
  * @package Box\Spout\Writer\Exception
  */
 class WriterNotOpenedException extends WriterException
diff --git a/src/Spout/Writer/ODS/Writer.php b/src/Spout/Writer/ODS/Writer.php
index edb2c89..4b35dfd 100644
--- a/src/Spout/Writer/ODS/Writer.php
+++ b/src/Spout/Writer/ODS/Writer.php
@@ -27,6 +27,7 @@ class Writer extends AbstractMultiSheetsWriter
      * Sets a custom temporary folder for creating intermediate files/folders.
      * This must be set before opening the writer.
      *
+     * @api
      * @param string $tempFolder Temporary folder where the files to create the ODS will be stored
      * @return Writer
      * @throws \Box\Spout\Writer\Exception\WriterAlreadyOpenedException If the writer was already opened
diff --git a/src/Spout/Writer/Style/Color.php b/src/Spout/Writer/Style/Color.php
index 346bfc2..3c86eb7 100644
--- a/src/Spout/Writer/Style/Color.php
+++ b/src/Spout/Writer/Style/Color.php
@@ -29,6 +29,7 @@ class Color
     /**
      * Returns an RGB color from R, G and B values
      *
+     * @api
      * @param int $red Red component, 0 - 255
      * @param int $green Green component, 0 - 255
      * @param int $blue Blue component, 0 - 255
diff --git a/src/Spout/Writer/Style/StyleBuilder.php b/src/Spout/Writer/Style/StyleBuilder.php
index 8629ca6..4619f43 100644
--- a/src/Spout/Writer/Style/StyleBuilder.php
+++ b/src/Spout/Writer/Style/StyleBuilder.php
@@ -24,6 +24,7 @@ class StyleBuilder
     /**
      * Makes the font bold.
      *
+     * @api
      * @return StyleBuilder
      */
     public function setFontBold()
@@ -35,6 +36,7 @@ class StyleBuilder
     /**
      * Makes the font italic.
      *
+     * @api
      * @return StyleBuilder
      */
     public function setFontItalic()
@@ -46,6 +48,7 @@ class StyleBuilder
     /**
      * Makes the font underlined.
      *
+     * @api
      * @return StyleBuilder
      */
     public function setFontUnderline()
@@ -57,6 +60,7 @@ class StyleBuilder
     /**
      * Makes the font struck through.
      *
+     * @api
      * @return StyleBuilder
      */
     public function setFontStrikethrough()
@@ -68,6 +72,7 @@ class StyleBuilder
     /**
      * Sets the font size.
      *
+     * @api
      * @param int $fontSize Font size, in pixels
      * @return StyleBuilder
      */
@@ -80,6 +85,7 @@ class StyleBuilder
     /**
      * Sets the font color.
      *
+     * @api
      * @param string $fontColor ARGB color (@see Color)
      * @return StyleBuilder
      */
@@ -92,6 +98,7 @@ class StyleBuilder
     /**
      * Sets the font name.
      *
+     * @api
      * @param string $fontName Name of the font to use
      * @return StyleBuilder
      */
@@ -105,6 +112,7 @@ class StyleBuilder
      * Makes the text wrap in the cell if it's too long or
      * on multiple lines.
      *
+     * @api
      * @return StyleBuilder
      */
     public function setShouldWrapText()
@@ -116,6 +124,7 @@ class StyleBuilder
     /**
      * Returns the configured style. The style is cached and can be reused.
      *
+     * @api
      * @return Style
      */
     public function build()
diff --git a/src/Spout/Writer/WriterFactory.php b/src/Spout/Writer/WriterFactory.php
index 9d468a6..7588940 100644
--- a/src/Spout/Writer/WriterFactory.php
+++ b/src/Spout/Writer/WriterFactory.php
@@ -18,6 +18,7 @@ class WriterFactory
     /**
      * This creates an instance of the appropriate writer, given the type of the file to be read
      *
+     * @api
      * @param  string $writerType Type of the writer to instantiate
      * @return WriterInterface
      * @throws \Box\Spout\Common\Exception\UnsupportedTypeException
diff --git a/src/Spout/Writer/XLSX/Writer.php b/src/Spout/Writer/XLSX/Writer.php
index 5927884..965955a 100644
--- a/src/Spout/Writer/XLSX/Writer.php
+++ b/src/Spout/Writer/XLSX/Writer.php
@@ -34,6 +34,7 @@ class Writer extends AbstractMultiSheetsWriter
      * Sets a custom temporary folder for creating intermediate files/folders.
      * This must be set before opening the writer.
      *
+     * @api
      * @param string $tempFolder Temporary folder where the files to create the XLSX will be stored
      * @return Writer
      * @throws \Box\Spout\Writer\Exception\WriterAlreadyOpenedException If the writer was already opened
@@ -50,6 +51,7 @@ class Writer extends AbstractMultiSheetsWriter
      * Use inline string to be more memory efficient. If set to false, it will use shared strings.
      * This must be set before opening the writer.
      *
+     * @api
      * @param bool $shouldUseInlineStrings Whether inline or shared strings should be used
      * @return Writer
      * @throws \Box\Spout\Writer\Exception\WriterAlreadyOpenedException If the writer was already opened