Update docs/upgrade-guide-2.md

Co-authored-by: Darrel <darrmi@microsoft.com>

Author: MaggieKimani1

docs/upgrade-guide-2.md

@@ -364,7 +364,7 @@ There are a number of new features in OpenAPI v3.1 that are now supported in Ope
 ### JsonSchema Dialect and BaseUri in OpenApiDocument
 To enable full compatibility with JSON Schema, the OpenApiDocument class now supports a jsonSchemaDialect property. This property specifies the JSON Schema dialect used throughout the document, using a URI. By explicitly declaring the dialect, tooling can be directed to use a JSON Schema version other than the default [2020-12 draft](https://json-schema.org/draft/2020-12/json-schema-core.html).  However, OpenAPI.NET does not guarantee compatibility with versions other than 2020-12.
 
-In addition, a BaseUri property has been added to represent the absolute location of the OpenAPI document. If the document’s location is not provided, this property will be set to a generated placeholder URI.
+In addition, a BaseUri property has been added to represent the identity of the OpenAPI document. If the document’s identity is not provided or cannot be determined at based on its location, this property will be set to a generated placeholder URI.
 
 ```csharp
 /// <summary>