---
layout: rule
id: GORULE:0000011
title: "ND evidence code should be to root nodes only, and no terms other than root nodes can have the evidence code ND"
type: filter
fail_mode: hard
status: implemented
contact: "go-quality@lists.stanford.edu"
implementations:
  - language: python
    source: https://github.com/biolink/ontobio/blob/master/ontobio/io/qc.py

---
The [No Data (ND) evidence code](http://www.geneontology.org/GO.evidence.shtml#nd) should be only used
for annotations to the root nodes: GO:0008150 biological_process, GO:0003674 molecular_function and GO:0005575 cellular_component. 

The root nodes: GO:0008150 biological_process, GO:0003674 molecular_function and GO:0005575 cellular_component can only be annotated with the [No Data (ND) evidence code](http://www.geneontology.org/GO.evidence.shtml#nd).  

Error report (number of errors) in [db_species]-report.html & owltools-check.txt (details).