diff --git a/_docs/download-mappings.md b/_docs/download-mappings.md
index b89e86b7..f61671d7 100644
--- a/_docs/download-mappings.md
+++ b/_docs/download-mappings.md
@@ -5,27 +5,27 @@ redirect_from: /page/download-mappings
---
# Cross-references to external classification systems
-Gene Ontology terms are mapped to commonly used bioinformatics resources whenver possible. These mappings (or "cross-references") help integrate GO and its annotations annotations with other biological databases and resources, creating a network of information that helps researchers to navigate across data types.
+Gene Ontology terms are mapped to commonly used bioinformatics resources whenver possible. These mappings (or "cross-references") create a network of information that integrate GO and its annotations with other biological databases and resources.
External classification systems mapped to GO terms:
|**Database resource** |**Scope**|**Relevant GO aspect(s)**|**Direct access to mapping file(s)**|
|--------|---------|---------|---------|
-|[Enzyme Commission (EC)](https://enzyme.expasy.org/){:target="blank"}| Reactions| Molecular Function |[ec2go](https://geneontology.org/external2go/ec2go)|
-|[KEGG: Kyoto Encyclopaedia of Genes and Genomes ](http://www.genome.jp/kegg/){:target="blank"} | Reactions |Molecular Function|[kegg_reaction2go](https://geneontology.org/external2go/kegg_reaction2go)|
+|[Enzyme Commission (EC)](https://enzyme.expasy.org/){:target="blank"}| Catalytic reactions| Molecular Function |[ec2go](https://geneontology.org/external2go/ec2go)|
+|[KEGG: Kyoto Encyclopaedia of Genes and Genomes ](http://www.genome.jp/kegg/){:target="blank"} | Catalytic reactions |Molecular Function|[kegg_reaction2go](https://geneontology.org/external2go/kegg_reaction2go)|
|[HAMAP](http://www.expasy.org/sprot/hamap/){:target="blank"} | High-Quality Automated and Manual Annotation of Microbial Proteomes |All aspects | [hamap2go](https://geneontology.org/external2go/hamap2go) |
|[InterPro](http://www.ebi.ac.uk/interpro/){:target="blank"} | Protein families, domains and functional sites. Ecnompasses contributing databases: [PantherDB](https://www.pantherdb.org/), [PFAM](http://pfam.xfam.org/), [PIRSF](https://proteininformationresource.org/pirsf/), [PRINTS], [PROSITE](https://prosite.expasy.org/) and [SMART](https://smart.embl-heidelberg.de/) |All aspects | [interpro2go](https://geneontology.org/external2go/interpro2go)|
-|[MetaCyc](http://metacyc.org/){:target="blank"} | Pathways and reactions |Molecular Function & Biological Process | [metacyc2go](https://geneontology.org/external2go/metacyc2go)|
+|[MetaCyc](http://metacyc.org/){:target="blank"} | Biological pathways and catalytic reactions |Molecular Function & Biological Process | [metacyc2go](https://geneontology.org/external2go/metacyc2go)|
|[Reactome](http://www.reactome.org/){:target="blank"} | Events and catalyst activities|Molecular Function |[reactome2go](https://geneontology.org/external2go/reactome2go)|
|[Rfam - RNA families](http://rfam.xfam.org/){:target="blank"}
| RNA entities| All aspects| [rfam2go](https://geneontology.org/external2go/rfam2go)|
-|[Rhea](https://www.rhea-db.org/){:target="blank"}| Reactions | Molecular Function|[rhea2go](https://geneontology.org/external2go/rhea2go)|
+|[Rhea](https://www.rhea-db.org/){:target="blank"}| Catalytic reactions | Molecular Function|[rhea2go](https://geneontology.org/external2go/rhea2go)|
|[UM-BBD](http://eawag-bbd.ethz.ch/aboutBBD.html){:target="blank"} | Biocatalysis/Biodegradation Database: enzymes, reactions and pathways |Molecular Function & Biological Process|[um-bbd_enzymeid2go](https://geneontology.org/external2go/um-bbd_enzymeid2go)
[um-bbd_reactionid2go](https://geneontology.org/external2go/um-bbd_reactionid2go)
[um-bbd_pathwayid2go](https://geneontology.org/external2go/um-bbd_pathwayid2go) |
|[UniProt Keywords](https://www.uniprot.org/keywords/){:target="blank"}| Mapping of GO terms to UniProt Knowledgebase keywords. | All aspects| [uniprotkb_kw2go](https://geneontology.org/external2go/uniprotkb_kw2go)|
-|[UniProt Subcellular location](https://www.uniprot.org/locations/){:target="blank"}| Mapping of GO terms to UniProt Subcellular location terms | Cellular Component| [uniprotkb_sl2go](https://geneontology.org/external2go/uniprotkb_sl2go)|
+|[UniProt Subcellular location](https://www.uniprot.org/locations/){:target="blank"}| UniProt Subcellular location terms | Cellular Component| [uniprotkb_sl2go](https://geneontology.org/external2go/uniprotkb_sl2go)|
|[UniRules](https://www.uniprot.org/help/unirule){:target="blank"}|UniProt Automatic Annotation pipeline| All aspects| [unirule2go](https://geneontology.org/external2go/unirule2go)|
[Wikipedia](https://www.wikipedia.org/){:target="blank"} | General | All aspects | [wikipedia2go](https://current.geneontology.org/ontology/external2go/wikipedia2go)
-Direct access to the mappings file directory is available here: [https://current.geneontology.org/ontology/external2go/](https://current.geneontology.org/ontology/external2go/).
+Direct access to the mappings file directory: [https://current.geneontology.org/ontology/external2go/](https://current.geneontology.org/ontology/external2go/).
## Cross-references files format
@@ -41,7 +41,7 @@ Direct access to the mappings file directory is available here: [https://current
For example: `EC:1.1.1.1 > GO:alcohol dehydrogenase (NAD+) activity ; GO:0004022`
## Mapping types & cardinality
-+ Certain types of cross-references to GO mappings can be many-to-many.
++ The cardinality of some of cross-references can be many-to-many; others are restricted.
+ Cross-references can be one of 4 types: exact, broad, narrow general database cross references
+ **Exact database cross references**: GO and cross reference object have the same meaning.
+ Cardinality: 1:1
@@ -54,7 +54,6 @@ Direct access to the mappings file directory is available here: [https://current
+ Cross references deprecated in the source database should not be included in GO.
## Using and citing cross-references and mappings
-
-If you have used a mapping in a publication or presentation, please ensure that you cite both the GO knowledgebase and the source of the mapping (detailed below). See the [GO citation guide](/docs/go-citation-policy/) for citing the GO knowledgebase.
+If you have used a mapping in a publication or presentation, please ensure that you cite both the GO knowledgebase and the source of the mapping. See the [GO citation guide](/docs/go-citation-policy/) for citing the GO knowledgebase.