During the creation of a layout handle you specify a node <label>
which is some text to describe the layout handle. For example the layout handle catalog_category_default
has the following defined.
<label>Catalog Category (Non-Anchor)</label>
As part of the layout handle you can specify to translate these labels <catalog_category_default translate="label">
. Which makes sense if these labels are shown some place but I am not sure if or where they are shown to a user and so would require translation.