document that state variables are not available in the checkconfig hook

diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn
index 45f083b423ca5b88117ce604ba5248431d6b32a3..082f0e38f589d50d2fd14b5f6637d1ddf6b91869 100644 (file)
--- a/doc/plugins/write.mdwn
+++ b/doc/plugins/write.mdwn
@@ -68,20 +68,21 @@ In roughly the order they are called.
 
 This allows for plugins to perform their own processing of command-line
 options and so add options to the ikiwiki command line. It's called during
-command line processing, with @ARGV full of any options that ikiwiki was
+command line processing, with `@ARGV` full of any options that ikiwiki was
 not able to process on its own. The function should process any options it
-can, removing them from @ARGV, and probably recording the configuration
-settings in %config. It should take care not to abort if it sees
+can, removing them from `@ARGV`, and probably recording the configuration
+settings in `%config`. It should take care not to abort if it sees
 an option it cannot process, and should just skip over those options and
-leave them in @ARGV.
+leave them in `@ARGV`.
 
 ### checkconfig
 
        hook(type => "checkconfig", id => "foo", call => \&checkconfig);
 
 This is useful if the plugin needs to check for or modify ikiwiki's
-configuration. It's called early in the startup process. The
-function is passed no values. It's ok for the function to call
+configuration. It's called early in the startup process. `%config`
+is populated at this point, but other state has not yet been loaded.
+The function is passed no values. It's ok for the function to call
 `error()` if something isn't configured right.
 
 ### refresh