added proper comments
diff --git a/lib/processors/epub_processor.php b/lib/processors/epub_processor.php
index 4cc9fa61c..89c5daf06 100644
--- a/lib/processors/epub_processor.php
+++ b/lib/processors/epub_processor.php
@@ -95,7 +95,9 @@ class EpubProcessor extends TextProcessor
*/
const MAX_DESCRIPTION_LEN = 2000;
/**
- * The maximum DOM level of data in OPF file
+ * The constant represents the number of
+ * child levels at which the data is present in
+ * the content.opf file.
*
* @const integer MAX_DOM_LEVEL
*/
@@ -181,8 +183,10 @@ class EpubProcessor extends TextProcessor
}
/**
- * Used to extract the DOM tree from
- * a string consisting of ebook publication content OPF file.
+ * Used to extract the DOM tree containing the information
+ * about the epub file such as title, author, language, unique
+ * identifier of the book from a string consisting of ebook publication
+ * content OPF file.
*
* @param string $page xml contents
*