Wonderful!

I guess my misunderstanding was to expected the digit in C2 to limit the assignment to 2 bytes, which it clearly does not.

Actually replacing C2 by C1 in your code like so: 
(@two[0..1], @four[0..3], $one) = unpack "C1 C4 C", $data;

print "@two | @four | $one";    # 65 66 | 67 68 69 70 |

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And warns for uninitialized likely undef. I am really missing the purpose of what the digit does!?

In reply to Re^2: unpack - array takes too many bytes by jjap
in thread unpack - array takes too many bytes by jjap

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