> 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/landscape-units/ls_unit.ele/obj_typ_no.md).

# obj\_typ\_no

The object ID of the element is a foreign key referencing the HRU ID in the HRU [connect](/io-docs/introduction-1/connectivity/hru.con.md) file.