Update gene-product-information-gpi-format-20.md

_docs/gene-product-information-gpi-format-20.md

@@ -68,23 +68,26 @@ The file format comprises 10 tab-delimited fields. Fields with multiple values (
 
 #### DB:DB Object ID
 The **DB** prefix is the database abbreviation (namespace) from which the unique identifier **DB Object ID** is drawn and must be one of the values from the set of GO database cross-references. The **DB:DB Object ID** is the combined identifier for the database object.
-This field is mandatory, cardinality 1.\
+This field is mandatory, cardinality 1.
 
 <!--In GPI 1.0 format, the identifier may reference a top-level primary gene or gene product identifier, or an identified variant of a gene or gene product, for example identifiers that specify distinct proteins produced by differential splicing, alternative translational starts, post-translational cleavage, or post-translational modification. Identifiers for functional RNAs and protein complexes can also be included in this column. 
     If the gene product is not a top-level gene or gene product identifier, the **Parent_Object_ID** field should contain the canonical form of the gene or gene product. 
     Note that while the **DB_Object_ID** is the identifier for a database object that may be used for annotation, it may or may not correspond exactly to what is described in a paper. For example, a paper describing functional characterization of a protein may result in annotations to the gene encoding the protein (gene ID in **DB_Object_ID**) or annotations to the protein (protein ID in **DB_Object_ID**), depending on annotation practice of the contributing group. 
 -->
 #### DB Object Symbol
-A (unique and valid) symbol to which the **DB:DB_Object_ID** is matched. No white spaces allowed.\
-This field is mandatory, cardinality 1.\
+A (unique and valid) symbol to which the **DB:DB_Object_ID** is matched. No white spaces allowed.
+
+This field is mandatory, cardinality 1.
 The **DB_Object_Symbol** field should contain a symbol that is recognizable to a biologist wherever possible (an abbreviation widely used in the literature, for example). It is not a unique identifier or an accession number (unlike the **DB:DB_Object_ID**), although IDs can be used as a **DB_Object_Symbol** if there is no more biologically meaningful symbol available (e.g., when an unnamed gene is annotated). ORF names can be used for otherwise unnamed genes or proteins. If gene products are annotated, the gene product symbol can be used if available. Many gene product annotation entries may share a gene symbol. 
 The text entered in the **DB_Object_Symbol** should refer to the entity in **DB:DB_Object_ID**. For example, several alternative transcripts from one gene may be annotated separately, each with specific gene product identifiers in **DB:DB_Object_ID**, but with the same gene symbol in the **DB_Object_Symbol** column. 
 #### DB Object Name
-The name of the gene or gene product in **DB:DB_Object_ID**.\
-This field is not mandatory, cardinality 0, 1 [white space allowed]\
+The name of the gene or gene product in **DB:DB_Object_ID**.
+
+This field is not mandatory, cardinality 0, 1 [white space allowed]
 The text entered in the **DB_Object_Name** and **DB_Object_Symbol** should refer to the entity in **DB:DBB_Object_ID**. 
 #### DB Object Synonym
-These entries may be a gene symbol or other text. Note that we strongly recommend that synonyms are included in the GPI file, as this aids the searching of GO.\
+These entries may be a gene symbol or other text. Note that we strongly recommend that synonyms are included in the GPI file, as this aids the searching of GO.
+
 This field is not mandatory, cardinality 0, 1, >1 [white space allowed]; for cardinality >1 use a pipe to separate entries (e.g. YFL039C|ABY1|END7|actin gene). 
 #### DB Object Type
 An ontology identifier for the type of gene or gene product being annotated. This field uses Sequence Ontology, Protein Ontology, and GO labels and must correspond to one of the [permitted GPI entity types](https://github.com/geneontology/go-annotation/blob/master/specs/gpad-gpi-2-0.md#gpi-entity-types) or a more granular child term: SO:0001217 (protein-coding gene)
@@ -95,28 +98,35 @@ protein 	protein 	PR:000000001 (protein)
 protein-containing complex 	protein-containing complex 	GO:0032991 (protein-containing complex)
 
 
-marker or uncloned locus 	genetic_marker 	SO:0001645; or any subtype of ncRNA in the Sequence Ontology. If the precise product type is unknown, gene_product should be used.\
-This field is mandatory, cardinality 1.\
+marker or uncloned locus 	genetic_marker 	SO:0001645; or any subtype of ncRNA in the Sequence Ontology. If the precise product type is unknown, gene_product should be used.
+
+This field is mandatory, cardinality 1.
 The object type (gene, transcript, protein, protein_complex, etc.) listed in the **DB_Object_Type** field must match the database entry identified by the **DB:DB_Object_ID**. Note that **DB_Object_Type** refers to the database entry (i.e. it represents a protein, functional RNA, etc.); this column does not reflect anything about the GO term or the evidence on which the annotation is based. 
 #### DB Object Taxon
-The NCBI taxon ID of the species encoding the gene product.\
-This field is mandatory, cardinality 1.\
+The NCBI taxon ID of the species encoding the gene product.
+
+This field is mandatory, cardinality 1.
 The taxon should be specified as a number with the prefix "taxon". 
 #### Encoded by
 For proteins and transcripts, **Encoded by** refers to the gene id that encodes those entities.
+
 This field is not mandatory, cardinality 0, 1, >1 ; for cardinality >1 use a pipe to separate entries. 
-#### Parent Protein CHANGE THIS TEXT
-If the **DB:DB_Object_ID** refers to a variant of a gene product, this column will hold the identifier of the gene product from which it was derived.\
-This field is mandatory, cardinality 1, when variant forms of a gene product (e.g. identifiers that specify distinct proteins produced by differential splicing, alternative translational starts, post-translational cleavage or post-translational modification) are represented in **DB:DB_Object_ID**. If the **DB:DB_Object_ID** refers to the canonical form of a gene product, this column should be blank.\
-The identifier used must be a standard 2-part global identifier, e.g. UniProtKB:OK0206 
-The entity in the **Parent_Object_ID** column may not necessarily be the canonical form of the gene product; the canonical form would be identifiable as an entry for that gene product in the GPI file that would have the **Parent_Object_ID** blank. 
+#### Parent Protein
+
+
+This field is optional, cardinality 0+; multiple identifiers should be pipe-separated.
 #### Protein Containing Complex Members
 
+
+This field is optional, cardinality 0+; multiple identifiers should be pipe-separated.
+
 #### DB_Xrefs
-Identifiers for the object in **DB:DB_Object_ID** found in other databases.\
-This field is optional, cardinality 0+; multiple identifiers should be pipe-separated.\
+Identifiers for the object in **DB:DB_Object_ID** found in other databases.
+
+This field is optional, cardinality 0+; multiple identifiers should be pipe-separated.
 Identifiers used must be a standard 2-part global identifiers, e.g. UniProtKB:OK0206 
+
 This column should be used to record IDs for this object in other databases; for gene products in model organism databases, this must include the UniProtKB ID, and may also include NCBI gene or protein IDs, etc. 
 #### Gene Product Properties
-This field is optional, cardinality 0+; multiple properties should be pipe-separated.\
+This field is optional, cardinality 0+; multiple properties should be pipe-separated.
 The Properties column can be filled with a pipe separated list of values in the format "property_name = property_value". There is a fixed vocabulary for the property names and this list can be extended when necessary. Supported properties will include: 'GO annotation complete', "Phenotype annotation complete' (the value for these two properties would be a date), 'Target set' (e.g. Reference Genome, Kidney etc.), 'Database subset' (e.g. Swiss-Prot, TrEMBL).