diff --git a/README.md b/README.md
index 7961e57..7d9b44b 100644
--- a/README.md
+++ b/README.md
@@ -33,6 +33,10 @@ domains:
   - subdomain2.example.com
 ```
 
+**NOTE:** Make sure you have manually registered each subdomain you are listing in your Ionos account.
+The script currently does not handle adding subdomains for you.
+Attempting to update the DNS entry for an unregistered domain will cause the API call to fail.
+
 You may optionally set a descriptive string which is sent along with the update:
 ```yaml
 description: "Dynamic DNS update."
@@ -40,3 +44,17 @@ description: "Dynamic DNS update."
 
 As of right now, I am actually not sure what the description is needed for, but the API requires it.
 The value displayed above is used by default, if you don't override it inside `config.yml`.
+
+### Regular DNS updates
+
+In order to keep your DNS records synchronized with your public IP address, you should run the update script periodically.
+As of this writing, Ionos limit dynamic DNS updates via API to 2 requests per minute, so don't send requests more frequently than that.
+
+In order to update your DNS IPs once every minute, call the script once a minute. (Duh!)
+You can set your crontab to the following to achieve this:
+
+```
+*/1 * * * * /path/to/dnsupdate.py
+```
+
+Just make sure that the script is executable and located in the same directory as `config.yml`.