diff --git a/api.md b/api.md
index b4ea096..8301382 100644
--- a/api.md
+++ b/api.md
@@ -1,17 +1,17 @@
-## API
-
-### Functions
-
-| Function | Description |
-| -------- | ----------- |
-| `plug#begin(path)` | Start vim-plug block |
-| `plug#end()` | End block, update &rtp, and load plugins when not `vim_starting` |
-| `plug#helptags()` | Regenerate help tags for all plugins |
-| `plug#load(names...)` | Load the plugins immediately |
-
-### Global variables
-
-| Variable | Type | Description |
-| -------- | ---- | ----------- |
-| `g:plug_home` | String | Directory to store/load plugins. Set by `plug#begin(path)` call. |
+## API
+
+### Functions
+
+| Function | Description |
+| -------- | ----------- |
+| `plug#begin(path)` | Start vim-plug block |
+| `plug#end()` | End block, update &rtp, and load plugins when not `vim_starting` |
+| `plug#helptags()` | Regenerate help tags for all plugins |
+| `plug#load(names...)` | Load the plugins immediately |
+
+### Global variables (read-only)
+
+| Variable | Type | Description |
+| -------- | ---- | ----------- |
+| `g:plug_home` | String | Directory to store/load plugins. Set by `plug#begin(path)` call. |
 | `g:plugs` | Dict | Information of plugins. Initialized by `plug#begin(path)` and incrementally set by `Plug` commands. |
\ No newline at end of file