29130, 21931 (Ray): document what typeset -t is for.

This replaces documenting what it isn't for.

ChangeLog

@@ -1,3 +1,8 @@
+2023-08-16  Peter Stephenson  <p.stephenson@samsung.com>
+
+	* 29130, 29131 (Ray): Doc/Zsh/builtins.yo: document what typeset
+	-t is for, not what it isn't for.
+
 2023-08-14  Jun-ichi Takimoto  <takimoto-j@kba.biglobe.ne.jp>
 
 	* 52037: Completion/Unix/Command/_date,

Doc/Zsh/builtins.yo

@@ -2320,8 +2320,10 @@ readonly). Special variables that have been made readonly retain their value
 and readonly attribute when made local.
 )
 item(tt(-t))(
-Tags the named parameters.  Tags have no special meaning to the shell.
-This flag has a different meaning when used with tt(-f); see above.
+Tags the named parameters.  Tags only exist to flag the parameter for
+the user's own purposes --- the list of tagged parameters can be queried
+using `tt(typeset -t)'.  Tags have no other use.  Note that the tt(-t)
+flag has a different meaning when used with tt(-f); see above.
 )
 item(tt(-u))(
 Convert the result to upper case whenever the parameter is expanded.