Small fix to documentation

* doc/org.texi (Setting tags): Remove misleading information.
* lisp/org.el (org-tag-alist): Fix consistency with
  `org-tag-persistent-alist'.

doc/org.texi

@@ -5055,14 +5055,15 @@ If at least one tag has a selection key then pressing @kbd{C-c C-c} will
 automatically present you with a special interface, listing inherited tags,
 the tags of the current headline, and a list of all valid tags with
 corresponding keys@footnote{Keys will automatically be assigned to tags which
-have no configured keys.}.  In this interface, you can use the following
-keys:
+have no configured keys.}.
+
+Pressing keys assigned to tags will add or remove them from the list of tags
+in the current line.  Selecting a tag in a group of mutually exclusive tags
+will turn off any other tags from that group.
+
+In this interface, you can also use the following special keys:
 
 @table @kbd
-@item a-zA-Z...
-Pressing keys assigned to tags will add or remove them from the list of
-tags in the current line.  Selecting a tag in a group of mutually
-exclusive tags will turn off any other tags from that group.
 @kindex @key{TAB}
 @item @key{TAB}
 Enter a tag in the minibuffer, even if the tag is not in the predefined
@@ -5072,16 +5073,21 @@ You can also add several tags: just separate them with a comma.
 @kindex @key{SPC}
 @item @key{SPC}
 Clear all tags for this line.
+
 @kindex @key{RET}
 @item @key{RET}
 Accept the modified set.
+
 @item C-g
 Abort without installing changes.
+
 @item q
 If @kbd{q} is not assigned to a tag, it aborts like @kbd{C-g}.
+
 @item !
 Turn off groups of mutually exclusive tags.  Use this to (as an
 exception) assign several tags from such a group.
+
 @item C-c
 Toggle auto-exit after the next change (see below).
 If you are using expert mode, the first @kbd{C-c} will display the

lisp/org.el

@@ -3553,12 +3553,12 @@ The value of this variable is an alist.  Associations either:
   (TAG . SELECT)
   (SPECIAL)
 
-where TAG is a tag as a string, SELECT is a case-sensitive
-letter, used to select that tag through the fast tag selection
-interface, and SPECIAL is one of the following keywords:
-`:startgroup', `:startgrouptag', `:grouptags', `:engroup',
-`:endgrouptag' or `:newline'.  These keywords are used to define
-a hierarchy of tags.  See manual for details.
+where TAG is a tag as a string, SELECT is character, used to
+select that tag through the fast tag selection interface, and
+SPECIAL is one of the following keywords: `:startgroup',
+`:startgrouptag', `:grouptags', `:engroup', `:endgrouptag' or
+`:newline'.  These keywords are used to define a hierarchy of
+tags.  See manual for details.
 
 When this variable is nil, Org mode bases tag input on what is
 already in the buffer.  The value can be overridden locally by