README.md in yieldmanager-0.9.10 vs README.md in yieldmanager-0.9.11

- old
+ new

@@ -19,11 +19,11 @@
 
 ```
 sudo gem install yieldmanager
 ```
 
-or if you're using [RVM](https://rvm.beginrescueend.com/) (and why on earth wouldn't you?)
+or if you're using [RVM](https://rvm.io/) (and why on earth wouldn't you?)
 
 ```
 gem install yieldmanager
 ```
 
@@ -97,9 +97,31 @@
 
 and you have an AR objects for a **creatives** table in the db, the
 SOAP parser will interpret the returned SOAP object as
 an AR Creative object, resulting in bizarre errors. Uniquely
 re-name your AR object to eliminate the conflict.
+
+### WSDL validation checks
+
+**NOTE** this feature is not thread-safe!
+
+Due to an unknown bug, soap4r occasionally reports that a field is required when it really isn't. If you get an error along the lines of
+
+```
+XSD::ValueSpaceError: {https://api.yieldmanager.com/types}enum_ad_tag_type: cannot accept ''
+```
+
+...you can disable this checking temporarily by calling
+
+```
+@ym.disable_check_restriction
+```
+
+When you're done with the call, re-enable it using
+
+```
+@ym.enable_check_restriction
+```
 
 ### Pagination
 
 Some calls return datasets too large to retrieve all at once.
 Pagination allows you to pull them back incrementally, handling