Documented the need to either specify a UI style file when loading a layout, or having it set to the root element beforehand.

Docs/Reference.dox

@@ -141,7 +141,7 @@ The full list of supported parameters, their datatypes and default values:
 - TripleBuffer (bool) Whether to use triple-buffering. Default false.
 - VSync (bool) Whether to wait for vertical sync when presenting rendering window contents. Default false.
 - Multisample (int) Hardware multisampling level. Default 1 (no multisampling.)
-- %RenderPath (string) Default renderpath resource name. Default empty, which causes forward rendering (CoreData/RenderPaths/Forward.xml) to be used.
+- %RenderPath (string) Default renderpath resource name. Default empty, which causes forward rendering (Bin/CoreData/RenderPaths/Forward.xml) to be used.
 - Shadows (bool) Shadow rendering enable. Default true.
 - LowQualityShadows (bool) Low-quality (1 sample) shadow mode. Default false.
 - %Sound (bool) %Sound enable. Default true.
@@ -1345,11 +1345,13 @@ To allow the elements react to mouse input, either a mouse cursor element must b
 
 \section UI_Defining Defining UI elements in XML
 
-User interface elements derive from Serializable, so they can be serialized to/from XML using their attributes. There are two distinct use cases for %UI definition files: either defining just the %UI element style and leaving the actual position and dimensions to be filled in later, or fully defining an %UI element layout. The default element style definitions, used for example by the editor and the debug console, are in the file Data/UI/DefaultStyle.xml.
+User interface elements derive from Serializable, so they can be serialized to/from XML using their attributes. There are two distinct use cases for %UI definition files: either defining just the %UI element style and leaving the actual position and dimensions to be filled in later, or fully defining an %UI element layout. The default element style definitions, used for example by the editor and the debug console, are in the file Bin/Data/UI/DefaultStyle.xml.
 
-The function \ref UI::LoadLayout "LoadLayout()" in UI will take an XML file and instantiate the elements defined in it. To be valid XML, there should be one root %UI element. An optional style XML file can be specified; the idea is to first read the element's style from that file, then fill in the rest from the actual layout XML file. This way the layout file can be relatively simple, as the majority of the data is already defined.
+The function \ref UI::LoadLayout "LoadLayout()" in UI will take an XML file and instantiate the elements defined in it. To be valid XML, there should be one root-level %UI element. An optional style XML file can be specified; the idea is to first read the element's style from that file, then fill in the rest from the actual layout XML file. This way the layout file can be relatively simple, as the majority of the data is already defined.
 
-See the elements' C++ code for all supported attributes, and look at the editor's user interface layouts in the Data/UI directory for examples. You can also use the Editor application to create UI layouts. The serialization format is similar to scene XML serialization, with three important differences:
+Note that a style can not be easily applied recursively to the loaded elements afterward. Therefore remember to specify the style file already when loading, or alternatively \ref UIElement::SetDefaultStyle "assign a default style file" to the %UI root element, which will then be picked up by all loaded layouts.
+
+See the elements' C++ code for all supported attributes, and look at the editor's user interface layouts in the Bin/Data/UI directory for examples. You can also use the Editor application to create %UI layouts. The serialization format is similar to scene XML serialization, with three important differences:
 
 1) The element type to instantiate, and the style to use for it can be set separately. For example the following element definition