edit entity and attribute annotation sections

Edited the text in the entity and attribute annotation sections

docs/eml-semantic-annotations-primer.md

@@ -36,11 +36,11 @@ Example `dataset` annotation:
 
 ## entity-level annotation
 
-Entities are usually tables of data (EML element `dataTable`). Data tables may be ascii text files, relational database tables, spreadsheets or other type of tabular data with a fixed logical structure. Related to data tables are views (EML element `view`) and stored procedures (EML element `storedProcedure`). Views and stored procedures are produced by an RDBMS or related system. Other types of data such as: raster (EML element `spatialRaster`), vector (EML element `spatialVector`) or spatialReference image data are also data entities. An `otherEntity` element would be used to describe types of entities that are not described by any other entity type. 
+Entities are usually tables of data (EML element `dataTable`). Data tables may be ascii text files, relational database tables, spreadsheets or other type of tabular data with a fixed logical structure. Related to data tables are views (EML element `view`) and stored procedures (EML element `storedProcedure`). Views and stored procedures are produced by an RDBMS or related system. Other types of data such as: raster (EML element `spatialRaster`), vector (EML element `spatialVector`) or spatialReference image data are also data entities. An `otherEntity` element would be used to describe types of entities that are not described by any other entity type. Entity-level EML elements are nested under `dataset` elements. Further information about entities may be found at: [insert link].
 
 An entity-level annotation represents a precisely-defined semantic statement that applies to an entity. This semantic statement is used to associate precise measurement semantics with the entity. An entity-level annotation is embedded in a containing entity-level element. The subject of the semantic statement is the entity-level element that contains the annotation. Each annotation consists of a `propertyURI` element and `valueURI` element, which respectively define a property and a value (object) that apply to the entity. The associated labels can be used to display the property and value in a more readable format to users. Each URI should be resolvable to a controlled vocabulary that provides a precise definition, relationships to other terms, and multiple labels for displaying the statement. 
 
-In the following entity-level annotation (Example 2), the subject of the semantic statement is the EML `otherEntity` element's `id` attribute value, "urn:uuid:9f0eb128-aca8-4053-9dda-8e7b2c43a81b". The object property of the statement is `http://purl.org/dc/elements/1.1/subject`. Finally, the value (object) in the semantic statement is `http://purl.obolibrary.org/obo/NCBITaxon_40674`, which resolves to the "Mammalia" term in the NCBITaxon ontology (http://www.ontobee.org/ontology/NCBITaxon). Taken together, the semantic statement indicates that "the entity with the id 'urn:uuid:9f0eb128-aca8-4053-9dda-8e7b2c43a81b' has the subject Mammalia".
+In the following entity-level annotation (Example 2), the subject of the semantic statement is the EML `otherEntity` element's `id` attribute value, "urn:uuid:9f0eb128-aca8-4053-9dda-8e7b2c43a81b". The object property of the statement is `http://purl.org/dc/elements/1.1/subject`. Finally, the value (object) in the semantic statement is `http://purl.obolibrary.org/obo/NCBITaxon_40674`, which resolves to the "Mammalia" term in the NCBITaxon ontology (http://www.ontobee.org/ontology/NCBITaxon). Taken together, the semantic statement indicates that "the entity with the id 'urn:uuid:9f0eb128-aca8-4053-9dda-8e7b2c43a81b' is about the subject Mammalia".
 
  * Example 2: entity-level annotation
 
@@ -63,7 +63,7 @@ In the following entity-level annotation (Example 2), the subject of the semanti
 
 ## attribute-level annotation
 
-An attribute is a characteristic that describes a 'field' or 'variable' in a data entity, such as a column name in a spreadsheet. An attribute annotation represents a precisely-defined semantic statement that applies to an attribute. This semantic statement is used to associate precise measurement semantics with the attribute, such as the property being measured, the entity being measured, and the measurement standard for interpreting values for the attribute. `attribute` elements may be nested in entity-level elements, including the `dataTable`, `spatialRaster`, `spatialVector`, `storedProcedure`, `view`, or `otherEntity` EML elements, in addition to custom modules. Refer to the Data Structures Modules for additional information about attributes [insert link].  
+An attribute is a characteristic that describes a 'field' or 'variable' in a data entity, such as a column name in a spreadsheet. An attribute annotation represents a precisely-defined semantic statement that applies to an attribute. This semantic statement is used to associate precise measurement semantics with the attribute, such as the property being measured, the entity being measured, and the measurement standard for interpreting values for the attribute. `attribute` elements may be nested in entity-level elements, including the `dataTable`, `spatialRaster`, `spatialVector`, `storedProcedure`, `view`, or `otherEntity` EML elements, in addition to custom modules. Refer to the Data Structures Modules documentation for additional information about attributes [insert link].  
 
 A typical attribute annotation is embedded in a containing EML `attribute` element. The subject of the semantic statement is the `attribute` element that contains the annotation. Each annotation consists of a `propertyURI` element and `valueURI` element that respectively define the property and value (object) of the semantic statement. The associated labels can be used to display the property and value in a more readable format to users. Each URI should be resolvable to a controlled vocabulary that provides a precise definition, relationships to other terms, and multiple labels for displaying the statement. Note that for annotating attributes that are measurements contained in tabular formats the preferred "default" object property is "contains measurements of type" (`http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#containsMeasurementsOfType`).