set_value

<textarea name="address[]"><?= set_value('address[]') ?></textarea>
<textarea name="address[]"><?= set_value('address[]') ?></textarea>
<textarea name="address[]"><?= set_value('address[]') ?></textarea>

When validation fails for one of the textarea inputs the fields are not being repopulated. (I don't see how this could work anyway)
It works fine when the names are not an array and I use address1, address2, and address3 instead.

Simpler is always better