diff --git a/Design-Doc%3A-%60level%60-tool.md b/Design-Doc%3A-%60level%60-tool.md
index 3250bbe..ca5f0ef 100644
--- a/Design-Doc%3A-%60level%60-tool.md
+++ b/Design-Doc%3A-%60level%60-tool.md
@@ -42,11 +42,18 @@ health = {
 ## .lvl Format
 The .lvl format is output by the `level` tool. It is a binary format ideal for use on a 8-bit or 16-bit game console. All coordinates use (0,0) upper left as an origin. 
 
+### Entity Data
+```
+2 byte: Number of entities
+For (number of entities):
+   * 2 bytes: Entity ID (-1 if not present)
+```
+
 ### Component Definitions
 ```
 * 2 bytes: Number of component definitions
 For (number of component definitions):
-   * 1 byte: ID for this component
+   * 2 bytes: ID for this component
    * 1 byte: Number of 16-bit properties associated with this component
       * Note: Order of fields are identical to order of fields in configuration TOML.
 ```