Merge branch '6.4' into 7.0

* 6.4:
  [AssetMapper] Removing orphaned footnote [2]
  Tweak
  [AssetMapper] Adding updater to comparison table
  doc: added a disambiguation on what the identifier is

frontend.rst

@@ -37,6 +37,7 @@ Supports TypeScript               :ref:`yes <asset-mapper-ts>`        yes
 Removes comments from JavaScript  no                                  yes
 Removes comments from CSS         no                                  no
 Versioned assets                  always                              optional
+Can update 3rd party packages     yes                                 no :ref:`[2] <ux-note-2>`
 ================================  ==================================  ==========
 
 .. _ux-note-1:
@@ -46,6 +47,10 @@ need to use their native tools for pre-compilation. Also, some features (like
 Vue single-file components) cannot be compiled down to pure JavaScript that can
 be executed by a browser.
 
+.. _ux-note-2:
+
+**[2]** If you use ``npm``, there are update checkers available (e.g. ``npm-check``).
+
 .. _frontend-asset-mapper:
 
 AssetMapper (Recommended)

security/access_token.rst

@@ -97,6 +97,8 @@ This handler must implement
             }
 
             // and return a UserBadge object containing the user identifier from the found token
+            // (this is the same identifier used in Security configuration; it can be an email,
+            // a UUUID, a username, a database ID, etc.)
             return new UserBadge($accessToken->getUserId());
         }
     }