diff --git a/includes/service.inc b/includes/service.inc
index 043f5b7..ff9133c 100644
--- a/includes/service.inc
+++ b/includes/service.inc
@@ -57,7 +57,7 @@ class SearchApiSolrService extends SearchApiAbstractService {
   protected $request_handler = NULL;
 
   /**
-   * Overrides SearchApiAbstractService::configurationForm().
+   * {@inheritdoc}
    */
   public function configurationForm(array $form, array &$form_state) {
     if ($this->options) {
@@ -271,7 +271,7 @@ class SearchApiSolrService extends SearchApiAbstractService {
   }
 
   /**
-   * Overrides SearchApiAbstractService::configurationFormValidate().
+   * {@inheritdoc}
    */
   public function configurationFormValidate(array $form, array &$values, array &$form_state) {
     if (isset($values['port']) && (!is_numeric($values['port']) || $values['port'] < 0 || $values['port'] > 65535)) {
@@ -280,7 +280,7 @@ class SearchApiSolrService extends SearchApiAbstractService {
   }
 
   /**
-   * Overrides SearchApiAbstractService::configurationFormSubmit().
+   * {@inheritdoc}
    */
   public function configurationFormSubmit(array $form, array &$values, array &$form_state) {
     // Since the form is nested into another, we can't simply use #parents for
@@ -495,7 +495,7 @@ class SearchApiSolrService extends SearchApiAbstractService {
   }
 
   /**
-   * Overrides SearchApiAbstractService::addIndex().
+   * {@inheritdoc}
    */
   public function addIndex(SearchApiIndex $index) {
     if (module_exists('search_api_multi') && module_exists('search_api_views')) {
@@ -504,7 +504,7 @@ class SearchApiSolrService extends SearchApiAbstractService {
   }
 
   /**
-   * Overrides SearchApiAbstractService::fieldsUpdated().
+   * {@inheritdoc}
    */
   public function fieldsUpdated(SearchApiIndex $index) {
     if (module_exists('search_api_multi') && module_exists('search_api_views')) {
@@ -525,7 +525,7 @@ class SearchApiSolrService extends SearchApiAbstractService {
   }
 
   /**
-   * Overrides SearchApiAbstractService::removeIndex().
+   * {@inheritdoc}
    */
   public function removeIndex($index) {
     if (module_exists('search_api_multi') && module_exists('search_api_views')) {
@@ -536,7 +536,7 @@ class SearchApiSolrService extends SearchApiAbstractService {
   }
 
   /**
-   * Implements SearchApiServiceInterface::indexItems().
+   * {@inheritdoc}
    */
   public function indexItems(SearchApiIndex $index, array $items) {
     $documents = array();
@@ -772,6 +772,17 @@ class SearchApiSolrService extends SearchApiAbstractService {
    *
    * It is up to the caller to ensure $ids is a valid query when the method is
    * called in this fashion.
+   *
+   * @param array|string $ids
+   *   Either an array containing the ids of the items that should be deleted,
+   *   or 'all' if all items should be deleted. Other formats might be
+   *   recognized by implementing classes, but these are not standardized.
+   * @param SearchApiIndex $index
+   *   The index from which items should be deleted, or NULL if all indexes on
+   *   this server should be cleared (then, $ids has to be 'all').
+   *
+   * @throws SearchApiException
+   *   If an error occurred while trying to delete the items.
    */
   public function deleteItems($ids = 'all', SearchApiIndex $index = NULL) {
     $this->connect();
@@ -804,7 +815,7 @@ class SearchApiSolrService extends SearchApiAbstractService {
   }
 
   /**
-   * Implements SearchApiServiceInterface::search().
+   * {@inheritdoc}
    */
   public function search(SearchApiQueryInterface $query) {
     $time_method_called = microtime(TRUE);
diff --git a/includes/solr_connection.inc b/includes/solr_connection.inc
index 13eeedd..a41ce05 100644
--- a/includes/solr_connection.inc
+++ b/includes/solr_connection.inc
@@ -224,7 +224,7 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::ping().
+   * {@inheritdoc}
    */
   public function ping($timeout = 2) {
     $start = microtime(TRUE);
@@ -251,28 +251,28 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::setSoftCommit().
+   * {@inheritdoc}
    */
   public function setSoftCommit($soft_commit) {
     $this->soft_commit = (bool) $soft_commit;
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::getSoftCommit().
+   * {@inheritdoc}
    */
   public function getSoftCommit() {
     return $this->soft_commit;
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::setStreamContext().
+   * {@inheritdoc}
    */
   public function setStreamContext($stream_context) {
     $this->stream_context = $stream_context;
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::getStreamContext().
+   * {@inheritdoc}
    */
   public function getStreamContext() {
     return $this->stream_context;
@@ -333,6 +333,9 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
 
   /**
    * Sets $this->luke with the metadata about the index from admin/luke.
+   *
+   * @param int $num_terms
+   *   (optional) The number of "top terms" to return.
    */
   protected function setLuke($num_terms = 0) {
     if (empty($this->luke[$num_terms])) {
@@ -360,7 +363,7 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::getFields().
+   * {@inheritdoc}
    */
   public function getFields($num_terms = 0) {
     $fields = array();
@@ -371,7 +374,7 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::getLuke().
+   * {@inheritdoc}
    */
   public function getLuke($num_terms = 0) {
     if (!isset($this->luke[$num_terms])) {
@@ -381,7 +384,7 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::getSolrVersion().
+   * {@inheritdoc}
    */
   public function getSolrVersion() {
     // Allow for overrides by the user.
@@ -430,7 +433,7 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::getStats().
+   * {@inheritdoc}
    */
   public function getStats() {
     if (!isset($this->stats)) {
@@ -440,7 +443,7 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::getStatsSummary().
+   * {@inheritdoc}
    */
   public function getStatsSummary() {
     $stats = $this->getStats();
@@ -506,7 +509,7 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::clearCache().
+   * {@inheritdoc}
    */
   public function clearCache() {
     if ($cid = $this->getCacheId()) {
@@ -545,7 +548,7 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::makeServletRequest().
+   * {@inheritdoc}
    */
   public function makeServletRequest($servlet, array $params = array(), array $options = array()) {
     // Add default params.
@@ -561,7 +564,19 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Central method for making a GET operation against this Solr Server
+   * Sends a GET request to the Solr server.
+   *
+   * @param string $url
+   *   The URL to which the request should be sent.
+   * @param array $options
+   *   Additional options for the request, as recognized by
+   *   drupal_http_request().
+   *
+   * @return object
+   *   The HTTP response, as returned by drupal_http_request().
+   *
+   * @throws SearchApiException
+   *   If an error occurs, either during sending or on the server side.
    */
   protected function sendRawGet($url, array $options = array()) {
     $options['method'] = 'GET';
@@ -571,7 +586,19 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Central method for making a POST operation against this Solr Server
+   * Sends a PUT request to the Solr server.
+   *
+   * @param string $url
+   *   The URL to which the request should be sent.
+   * @param array $options
+   *   Additional options for the request, as recognized by
+   *   drupal_http_request().
+   *
+   * @return object
+   *   The HTTP response, as returned by drupal_http_request().
+   *
+   * @throws SearchApiException
+   *   If an error occurs, either during sending or on the server side.
    */
   protected function sendRawPost($url, array $options = array()) {
     $options['method'] = 'POST';
@@ -588,6 +615,15 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
    * Sends an HTTP request to Solr.
    *
    * This is just a wrapper around drupal_http_request().
+   *
+   * @param string $url
+   *   The URL to which the request should be sent.
+   * @param array $options
+   *   Additional options for the request, as recognized by
+   *   drupal_http_request().
+   *
+   * @return object
+   *   The HTTP response, as returned by drupal_http_request().
    */
   protected function makeHttpRequest($url, array $options = array()) {
     if (empty($options['method']) || $options['method'] == 'GET' || $options['method'] == 'HEAD') {
@@ -631,7 +667,7 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::escape().
+   * {@inheritdoc}
    */
   public static function escape($value, $version = 0) {
     $replacements = array();
@@ -651,7 +687,7 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::escapePhrase().
+   * {@inheritdoc}
    */
   public static function escapePhrase($value) {
     $replacements['"'] = '\"';
@@ -660,14 +696,14 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::phrase().
+   * {@inheritdoc}
    */
   public static function phrase($value) {
     return '"' . self::escapePhrase($value) . '"';
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::escapeFieldName().
+   * {@inheritdoc}
    */
   public static function escapeFieldName($value) {
     $value = str_replace(':', '\:', $value);
@@ -685,6 +721,7 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
    *   Additional query string to append to the URL.
    *
    * @return string
+   *   The complete URL.
    */
   protected function constructUrl($servlet, array $params = array(), $added_query_string = NULL) {
     // PHP's built in http_build_query() doesn't give us the format Solr wants.
@@ -704,14 +741,14 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::getBaseUrl().
+   * {@inheritdoc}
    */
   public function getBaseUrl() {
     return $this->base_url;
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::setBaseUrl().
+   * {@inheritdoc}
    */
   public function setBaseUrl($url) {
     $this->base_url = $url;
@@ -719,7 +756,7 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::update().
+   * {@inheritdoc}
    */
   public function update($rawPost, $timeout = 3600) {
     if (empty($this->update_url)) {
@@ -735,7 +772,7 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::addDocuments().
+   * {@inheritdoc}
    */
   public function addDocuments(array $documents, $overwrite = NULL, $commitWithin = NULL) {
     $attr = '';
@@ -759,21 +796,21 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::commit().
+   * {@inheritdoc}
    */
   public function commit($waitSearcher = TRUE, $timeout = 3600) {
     return $this->optimizeOrCommit('commit', $waitSearcher, $timeout);
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::deleteById().
+   * {@inheritdoc}
    */
   public function deleteById($id, $timeout = 3600) {
     return $this->deleteByMultipleIds(array($id), $timeout);
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::deleteByMultipleIds().
+   * {@inheritdoc}
    */
   public function deleteByMultipleIds(array $ids, $timeout = 3600) {
     $rawPost = '<delete>';
@@ -787,7 +824,7 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::deleteByQuery().
+   * {@inheritdoc}
    */
   public function deleteByQuery($rawQuery, $timeout = 3600) {
     $rawPost = '<delete><query>' . htmlspecialchars($rawQuery, ENT_NOQUOTES, 'UTF-8') . '</query></delete>';
@@ -796,14 +833,14 @@ class SearchApiSolrConnection implements SearchApiSolrConnectionInterface {
   }
 
   /**
-   * Implements SearchApiSolrConnectionInterface::optimize().
+   * {@inheritdoc}
    */
   public function optimize($waitSearcher = TRUE, $timeout = 3600) {
     return $this->optimizeOrCommit('optimize', $waitSearcher, $timeout);
   }
 
   /**
-   * Sends an commit or optimize command to the Solr server.
+   * Sends a commit or optimize command to the Solr server.
    *
    * Will be synchronous unless $waitSearcher is set to FALSE.
    *
diff --git a/includes/solr_connection.interface.inc b/includes/solr_connection.interface.inc
index 8e48dcb..fd66c2c 100644
--- a/includes/solr_connection.interface.inc
+++ b/includes/solr_connection.interface.inc
@@ -228,7 +228,7 @@ interface SearchApiSolrConnectionInterface {
   /**
    * Sends a delete request for several documents, based on the document IDs.
    *
-   * @param array $id
+   * @param array $ids
    *   The IDs of the documents which should be deleted. Expected to be UTF-8
    *   encoded.
    * @param int|false $timeout
@@ -306,8 +306,8 @@ interface SearchApiSolrConnectionInterface {
    *
    * @param string $value
    *   The string to escape.
-   * @param string $version
-   *   An integer representing major solr version release.
+   * @param int $version
+   *   An integer representing the major solr version.
    *
    * @return string
    *   An escaped string suitable for passing to Solr.