Premise: How to address envelopes with attn<br>Write " attn " followed by the name of the recipient. The " attn " line should always appear at the very top of your delivery address, just before the name of the person you're sending it to. Use a colon after " attn " to make it clearly readable.
Hypothesis: The colon in the top line of the delivery address on an envelope, located after "attn," is used to make the line clearly readable.