Suggested documentation for C<for> in Perl 6

for.txt

=head2 for

The C<for> loop iterates over a list.

=begin code

for @foo {.print}

=end code

Use pointy block syntax to get an iteration variable.

=begin code

for @foo -> $item { print $item }

=end code

Multiple parameters can be declared.

=begin code

for %hash.kv -> $key, $value { print "$key => $value\n" }

=end code

The list in a C<for> loop is evaluated lazily by default, so so to read a file line by line, you could use

=begin code

for $*IN.lines -> $line {...}

=end code

Iteration variables are always lexical, so you don't need to use C<my> to give
them the appropriate scope. Also, they are read-only aliases. If you need them
to be read-write, use C«<->» instead of C«->». If you need to make C<$_>
read-write in a for loop, do so explicitly.

=begin code

for @cars <-> $_ {...}

=end code

if this isn't going in the 5 to 6 section, I'd leave out the reference to 5 behavior. dha++

parameters vs arguments

Maybe
Multiple parameters can be declared
or
Multiple arguments can be passed

Edited to include coke and raiph's suggestions.