diff --git a/core/block.class.php b/core/block.class.php
index 737841e5..f672df9f 100644
--- a/core/block.class.php
+++ b/core/block.class.php
@@ -1,4 +1,14 @@
 <?php
+/*
+ * A basic chunk of page
+ *  $header -- the block's title
+ *  $body   -- the content
+ *  $section -- where the block should be placed. The default theme supports
+ *              "main" and "left", other themes can add their own areas
+ *  $position -- how far down the section the block should appear, higher
+ *               numbers appear lower. The scale is 0-100 by convention,
+ *               though any number or string will work.
+ */
 class Block {
 	var $header;
 	var $body;
@@ -13,6 +23,11 @@ class Block {
 	}
 }
 
+
+/*
+ * A generic navigation block with a link to the main page. Used
+ * because "new NavBlock()" is easier than "new Block('Navigation', ..."
+ */
 class NavBlock extends Block {
 	public function NavBlock() {
 		$this->header = "Navigation";
diff --git a/core/config.class.php b/core/config.class.php
index 8ff8f3ef..218c6c2b 100644
--- a/core/config.class.php
+++ b/core/config.class.php
@@ -1,12 +1,23 @@
 <?php
+/*
+ * A class for easy access to the 'config' table, can always be accessed
+ * through "global $config;"
+ */
 class Config {
 	var $values = array();
 	var $database = null;
 
+	/*
+	 * Load the config table from a database
+	 */
 	public function Config($database) {
 		$this->database = $database;
 		$this->values = $this->database->db->GetAssoc("SELECT name, value FROM config");
 	}
+
+	/*
+	 * Save the current values as the new config table
+	 */
 	public function save($name=null) {
 		if(is_null($name)) {
 			foreach($this->values as $name => $value) {
diff --git a/core/database.class.php b/core/database.class.php
index 0696f10b..845b07ba 100644
--- a/core/database.class.php
+++ b/core/database.class.php
@@ -2,7 +2,10 @@
 $ADODB_CACHE_DIR="./data";
 require_once "lib/adodb/adodb.inc.php";
 
-class Querylet { // {{{
+/* Querylet {{{
+ * A fragment of a query, used to build large search queries
+ */
+class Querylet {
 	var $sql;
 	var $variables;
 	
@@ -25,6 +28,9 @@ class Querylet { // {{{
 	}
 } // }}}
 
+/*
+ * A class for controlled database access, available through "global $database"
+ */
 class Database {
 	var $db;
 	var $extensions;
diff --git a/core/extension.class.php b/core/extension.class.php
index be7d23c2..1ee2a79f 100644
--- a/core/extension.class.php
+++ b/core/extension.class.php
@@ -1,4 +1,7 @@
 <?php
+/*
+ * A generic extension class, for subclassing
+ */
 class Extension {
 	public function receive_event($event) {}
 }
diff --git a/core/image.class.php b/core/image.class.php
index 288fc40d..dcc4351f 100644
--- a/core/image.class.php
+++ b/core/image.class.php
@@ -1,5 +1,9 @@
 <?php
-
+/*
+ * An object representing an entry in the images table. As of 2.2, this no
+ * longer necessarily represents an image per se, but could be a video,
+ * sound file, or any other supported upload type.
+ */
 class Image {
 	var $id = null;
 	var $height, $width;
@@ -9,15 +13,11 @@ class Image {
 	var $posted;
 	var $source;
 
-	public function Image($a=null) {
-		if(!is_null($a)) {
-			$this->create_from_row($a);
-		}
-	}
-
-	private function create_from_row($row) {
-		foreach($row as $name => $value) {
-			$this->$name = $value; // hax
+	public function Image($row=null) {
+		if(!is_null($row)) {
+			foreach($row as $name => $value) {
+				$this->$name = $value; // hax
+			}
 		}
 	}
 
diff --git a/core/user.class.php b/core/user.class.php
index 0241050f..0174b2d4 100644
--- a/core/user.class.php
+++ b/core/user.class.php
@@ -1,4 +1,7 @@
 <?php
+/*
+ * An object representing a row in the "users" table.
+ */
 class User {
 	var $id;
 	var $name;