Added a little more documentation, a=chris

diff --git a/src/library/BPlusTree.php b/src/library/BPlusTree.php
index abef3e927..581c0870d 100644
--- a/src/library/BPlusTree.php
+++ b/src/library/BPlusTree.php
@@ -93,11 +93,13 @@ class BPlusTree
     /**
      * Field variable used as a cache for the file handle, file name, and
      * time of the last archive file for a B+-tree node added to
+     * @var array
      */
     public $add_archive_cache = [null, "", -1];
     /**
      * Field variable used as a cache for the file handle, file name, and
      * time of the last archive file for a B+-tree node accessed for a value
+     * @var array
      */
     public $get_archive_cache = [null, "", -1];
     /**
diff --git a/src/library/IndexDocumentBundle.php b/src/library/IndexDocumentBundle.php
index a6c186845..b0684e75c 100644
--- a/src/library/IndexDocumentBundle.php
+++ b/src/library/IndexDocumentBundle.php
@@ -813,7 +813,7 @@ class IndexDocumentBundle implements CrawlConstants
     /**
      * Checks if a doc_id correspons to a document or a link
      *
-     * @param string $key
+     * @param string $key to check if doc or not
      * @return bool true if a document
      */
     public function isDoc($key)
@@ -1100,6 +1100,7 @@ class IndexDocumentBundle implements CrawlConstants
      * Returns the last time the archive info of the bundle was modified.
      *
      * @param string $dir_name folder with archive bundle
+     * @returb mixed either time if file exists or false
      */
     public static function getParamModifiedTime($dir_name)
     {