More updates after self-review

modules/n1ql/pages/n1ql-language-reference/collectionops.adoc

@@ -6,7 +6,7 @@
 :keywords: range condition, quantified expression
 
 {description}
-The operators include <<range-cond>>, <<range-xform>>, and <<membership-and-existence>>.
+The operators include <<range-cond>>, <<range-xform>>, and <<membership-and-existence-tests>>.
 
 NOTE: Although collection operators can be used with any array, they are particularly useful when used to evaluate expressions over an array of objects.
 The term _collection_ is used here in a generic sense to refer to any array of objects, rather than in the specific sense of a xref:learn:data/scopes-and-collections.adoc[Couchbase collection].
@@ -41,7 +41,7 @@ image::n1ql-language-reference/range.png["Syntax diagram", align=left]
 [discrete]
 ==== Arguments
 
-name-var:: An xref:n1ql-language-reference/identifiers.adoc[identifier] that represents the position of a single element in an array, counting from 0.
+name-var:: [Optional] An xref:n1ql-language-reference/identifiers.adoc[identifier] that represents the position of a single element in an array, counting from 0.
 
 var:: An xref:n1ql-language-reference/identifiers.adoc[identifier] that represents a single element in an array.
 
@@ -315,13 +315,13 @@ image::n1ql-language-reference/range.png["Syntax diagram", align=left]
 [discrete]
 ==== Arguments
 
-name-expr:: [Objects only] An xref:n1ql-language-reference/index.adoc#N1QL_Expressions[expression] that resolves to a string, to use as the name of an attribute in the output.
+name-expr:: [`OBJECT` only] An xref:n1ql-language-reference/index.adoc#N1QL_Expressions[expression] that resolves to a string, to use as the name of an attribute in the output.
 This expression may make use of the `var` and `name-var` identifiers as required.
 
 var-expr:: An xref:n1ql-language-reference/index.adoc#N1QL_Expressions[expression] that returns a value to include in the output.
 This expression may make use of the `var` and `name-var` identifiers as required.
 
-name-var:: An xref:n1ql-language-reference/identifiers.adoc[identifier] that represents the position of a single element in an array, counting from 0.
+name-var:: [Optional] An xref:n1ql-language-reference/identifiers.adoc[identifier] that represents the position of a single element in an array, counting from 0.
 
 var:: An xref:n1ql-language-reference/identifiers.adoc[identifier] that represents a single element in an array.
 
@@ -540,6 +540,7 @@ The value of each attribute in the output object is the output of the `var-expr`
 
 The name of each attribute in the output object is specified by the `name-expr` argument.
 This argument must be an expression that generates a unique name string for every value in the output object.
+If the expression does not generate a string, then the current attribute is not output.
 If the expression does not generate a unique name string for each value, then only the last attribute is output; all previous attributes are suppressed.
 
 The `name-expr` argument may reference the `var` argument or the `name-var` argument, or use any other expression that generates a unique value.
@@ -650,7 +651,7 @@ Notice that the position of each element in the input array is calculated _befor
 Refer to <<ArrayEx0b>> for another example with position variables.
 ====
 
-[[membership-and-existence,Membership and Existence Tests]]
+[[membership-and-existence-tests,Membership and Existence Tests]]
 == Membership and Existence
 
 Membership tests (<<collection-op-in>> and <<collection-op-within>>) enable you to test whether a value exists within an array.