Builtins

compctl -j -P % fg bg wait jobs disown
Completes job names (the first word of the job leader's command line) for fg bg wait jobs disown, but first prfixes them with %.

compctl -A shift
Completes array names for shift.

compctl -caF type whence which
Completes commands, aliases, and function names for type whence which.

compctl -F unfunction
Completes only function names for unfunction
compctl -a unalias
Completes only aliases for unalias
compctl -v unset typeset declare vared readonly export integer
Completes variable names for unset typeset declare vared readonly export integer

compctl -e disable
Completes only enabled and executable commands

compctl -d enable
Completes disabled commands

compctl -k '(cputime filesize datasize stacksize coredumpsize resident memoryuse memorylocked descriptors openfiles vmemorysize)' limit ulimit
Completes names from the elements of the array, explicitly defined here.
compctl -l '' -x 'p[1]' -f -- . source
The -l restricts the range of command line words to complete on.