Added non-normative note on the behaviour of the string stored in [[L…

…ocale]] field as pertains to U Extensions.

spec/negotiation.html

@@ -260,7 +260,7 @@ <h1>ResolveLocale ( _availableLocales_, _requestedLocales_, _options_, _relevant
       </emu-alg>
 
       <emu-note>
-        Non-normative summary: Two algorithms are available to match the locales: the Lookup algorithm described in RFC 4647 section 3.4, and an implementation dependent best-fit algorithm. Independent of the locale matching algorithm, options specified through Unicode locale extension sequences are negotiated separately, taking the caller's relevant extension keys and locale data as well as client-provided options into consideration. The abstract operation returns a record with a [[locale]] field whose value is the language tag of the selected locale, and fields for each key in _relevantExtensionKeys_ providing the selected value for that key.
+        Non-normative summary: Two algorithms are available to match the locales: the Lookup algorithm described in RFC 4647 section 3.4, and an implementation dependent best-fit algorithm. Independent of the locale matching algorithm, options specified through Unicode locale extension sequences are negotiated separately, taking the caller's relevant extension keys and locale data into consideration as well as the client-provided options. The abstract operation returns a Record with fields for each key in _relevantExtensionKeys_ that contains the selected values for those keys. This Record also contains a [[locale]] field which stores the language tag, but with whatever U Extensions tags that are not in _relevantExtensionKeys_ removed. If a property is set by an option and also specified in the locale extension sequence, the value from the option is used to set the property's value and the overridden extension tag is likewise removed from the string stored in [[locale]].
       </emu-note>
     </emu-clause>