> For the complete documentation index, see [llms.txt](https://swatplus.gitbook.io/io-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://swatplus.gitbook.io/io-docs/introduction-1/routing-units/untitled-1/elements.md).

# elements

If [elem\_tot](/io-docs/introduction-1/routing-units/untitled-1/elem_tot.md) = 1, there can be only one element in the Routing Unit, whose ID ([id](/io-docs/introduction-1/routing-units/untitled-2/id-rout_unit.ele.md) in [**rout\_unit.ele**](/io-docs/introduction-1/routing-units/untitled-2.md)) is specified in this column. If [elem\_tot](/io-docs/introduction-1/routing-units/untitled-1/elem_tot.md) > 1, this column is followed by additional columns listing the elements included in the Routing Unit, but those columns will not have a header. If there are several elements with consecutive numbers in a Routing Unit, they can be listed by specifying the first one in one column and the last one with a hyphen in front of it in the next column.