For starters, the syntax would be 

# 'categories' entry is 'GNOME;Games;Action'
push @{ $out{GNOME}{Games}{Action} }, $val;
# 'GNOME;Games;Action;FPS'
push @{ $out{GNOME}{Games}{Action}{FPS} }, $val;
# ...and so on.

[download]

But you got another problem. You're trying to get an array reference and a hash reference to coexist in the same variable. 

$out{GNOME}{Games}{Action}[0] = $val;
$out{GNOME}{Games}{Action}{FPS}[0] = $val;
                          ^
                          |
                         XXX

[download]

Perhaps you could use the items of a specific category could be placed into a special* key. Say "_". 

$out{GNOME}{Games}{Action}{_}[0] = $val;
$out{GNOME}{Games}{Action}{FPS}{_}[0] = $val;
                          ^
                          |
                          Ok

[download]

* — Special to you, not to Perl.

In reply to Re: Building an arbitrary-depth, multi-level hash by ikegami
in thread Building an arbitrary-depth, multi-level hash by Anonymous Monk

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