fix: removes confusing paragraph

Author: baywet

versions/1.2.0-dev.md

@@ -69,11 +69,9 @@ Overlay Description authors SHOULD consider how text using such extensions will
 
 Implementations MUST NOT treat an `extends` value as unresolvable before checking all possible target [[OpenAPI]] Description documents provided to the implementation.
 
-To ensure portability, when a target [[OpenAPI]] Description defines `$self`, the Overlay's `extends` value SHOULD match the target's `$self` URI.
+To ensure portability, when a target [[OpenAPI]] Description defines `$self`, the Overlay's `extends` value SHOULD match the target's `$self` URI.
 Implementations MUST examine all available target documents for matching `$self` values before concluding that no document matches the `extends` URI.
 
-Implementations MAY also support retrieval URI matching, which can be useful when `$self` is not defined in the target document.
-
 ### Relative References in URIs
 
 URIs used in an Overlay document, including `$self` and `extends`, are identifiers, and not necessarily locators (URLs).