License expression annex re-do

docs/annexes/SPDX-license-expressions.md

@@ -11,9 +11,9 @@ The exact syntax of license expressions is described below in ABNF, as defined i
 ```text
 idstring = 1*(ALPHA / DIGIT / "-" / "." )
 
-license-id = <short form license identifier in Annex A.1>
+license-id = <short form license identifier from SPDX License List>
 
-license-exception-id = <short form license exception identifier in Annex A.2>
+license-exception-id = <short form license exception identifier from SPDX License List>
 
 license-ref = [%s"DocumentRef-"(idstring)":"]%s"LicenseRef-"(idstring)
 
@@ -56,11 +56,9 @@ License identifiers (including license exception identifiers) used in SPDX docum
 
 However, please be aware that it is often important to match with the case of the canonical identifier on the [SPDX License List](https://spdx.org/licenses). This is because the canonical identifier's case is used in the URL of the license's or exception's entry on the List, and because the canonical identifier is translated to a URI in RDF documents.
 
-For license identifiers, only the variable part (after `LicenseRef-`) is case insensitive.
+For user defined license identifiers, only the variable part (after `LicenseRef-`) is case insensitive.  This means, for example, that `LicenseRef-Name` and `LicenseRef-name` should be treated as the same identifier and considered to refer to the same license, while `licenseref-name` is not a valid license identifier.
 
-This means, for example, that `LicenseRef-Name` and `LicenseRef-name` should be treated as the same identifier and considered to refer to the same license, while `licenseref-name` is not a valid license identifier.
-
-The same applies to `AdditionRef-`.
+The same applies to `AdditionRef-` user defined identifiers.
 
 ## D.3 Simple license expressions <a name="D.3"></a>