Merge pull request #3723 from handrews/space-delim

Clarify `spaceDelimited` with spaces (3.0.4)

Author: ralfhandl

versions/3.0.4.md

@@ -1058,6 +1058,7 @@ spaceDelimited | `array`, `object` | `query` | Space separated array values or o
 pipeDelimited | `array`, `object` | `query` | Pipe separated array values or object properties and values. This option replaces `collectionFormat` equal to `pipes` from OpenAPI 2.0.
 deepObject | `object` | `query` | Provides a simple way of rendering nested objects using form parameters.
 
+The behavior of applying a style that uses a delimiter to data containing that delimiter is not defined, and is therefore NOT RECOMMENDED.  To ensure interoperability, any such delimiter characters need to be escaped prior to serializing with the style, and unescaped after parsing.  In the case of `spaceDelimited`, care must be taken to avoid confusing interactions with URL parameter encoding of spaces.
 
 ##### Style Examples