Remind me about oddball reserved words

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

Here's the entire (11 lines) doc for reserved words:

##
6.5 Reserved Words
==================

The following words are recognized as reserved words when used as the
first word of a command unless quoted or disabled using disable -r:

do done esac then elif else fi for case if while function repeat time
until select coproc nocorrect foreach end ! [[ { }

Additionally, `}' is recognized in any position if neither the
IGNORE_BRACES option nor the IGNORE_CLOSE_BRACES option is set.
##

Close brace is recognized as a reserved word in command position?  I've
entirely forgotten why and would like to be reminded.  Also, why close
brace and not close-double-bracket?