Issue #118: document the whitelist.

diff --git a/readme_template.md b/readme_template.md
index 80fae4f416dde4365c60b9c0546b1ede3da41183..a7f3b73305bfc24bc96648f08f51fc1f0650e907 100644 (file)
--- a/readme_template.md
+++ b/readme_template.md
@@ -79,11 +79,24 @@ Add one or more  *additional* sources, each in a subfolder of the `data/` folder
 Add one or more *optional* extensions, which originate from subfolders of the `extensions/` folder.  Again the url in
 `update.info` controls where this extension finds its updates.
 
-## How do I incorporate my own hosts?
+### How do I include my own custom domain mappings?
 
 If you have custom hosts records, place them in file `myhosts`.  The contents of this file are prepended to the
 unified hosts file during the update process.
 
+The `myhosts` file is not tracked by git, so any changes you make won't be overridden when you `git pull` this repo from `origin` in the future.
+
+### How do I prevent domains from being included?
+
+The domains you list in the `whitelist` file are excluded from the final hosts file.  
+
+The `whitelist` uses partial matching.  Therefore if you whitelist `google-analytics.com`, that domain and all its
+subdomains won't be merged into the final hosts file.
+
+The `whitelist` is not tracked by git, so any changes you make won't be overridden when you `git pull` this repo 
+from `origin` in the future.
+
+
 ## What is a hosts file?
 
 A hosts file, named `hosts` (with no file extension), is a plain-text file used by all operating