Some fields can contain multiple rows of information, for example Taxonomies, Repeater fields, Recurring date fields, Gallery fields, File fields etc. We refer to these as Loopable fields.

The First item mod retrieves the value from specified dynamic tag from the first row e.g first category name

@post(category.name).first()

The Last item mod retrieves the value from last row, in this case last category name

@post(category.name).last()

And the Nth item, can retrieve an item by index (first is 0). Negative indexes are allowed (e.g., -1 for last item). For example, third category name

@post(category.name).nth(3)