diff --git a/modules/block/block.api.php b/modules/block/block.api.php
index 312eb11..5e2449b 100644
--- a/modules/block/block.api.php
+++ b/modules/block/block.api.php
@@ -286,6 +286,13 @@ function hook_block_view_alter(&$data, $block) {
  * Modules can implement hook_block_view_MODULE_DELTA_alter() to modify a
  * specific block, rather than implementing hook_block_view_alter().
  *
+ * PLEASE NOTE: When using hook_block_view_MODULE_DELTA_alter for menus that you
+ * would like to alter, please keep in mind that in drupal 7 the block module
+ * will convert hyphens (-) into underscores (_) and that function names with
+ * hyphens will trigger a php fatal error. You can either go back and make your
+ * menu machine name without hyphens OR change your hook definition to account
+ * for this.
+ *
  * @param $data
  *   An array of data, as returned from the hook_block_view() implementation of
  *   the module that defined the block: