anchor.diff:  
   This CIP also introduces an additional nullable type called `VOID`. `VOID` is intended to be used as the return type of user defined procedures that execute without producing a result value, i.e. the return type of procedures with side effects. `VOID` is a subtype of `ANY?`. In an expression context, `NULL` is the only value that inhibits the `VOID` type, indicating a missing "real" return value (Note though that Cypher currently does not have any expressions of type `VOID` and this is merely defined here for completeness).
   
  -==== Reserved type names
  -
  -In addition to the types above, the following type names are reserved by this CIP for future use, both in the given material and a nullable variant:
  -
  - * `BYTES`
  - * `IDENTITY`
  - * `POINT`
  -
   === Type Annotation
   
   To specify the type of a term in future changes to the Cypher grammar, this CIP proposes using the following syntax
  
positive.code: They could be added instead at a later stage.
  
  *Example*
  `RETURN [1, "Yo"] :: LIST OF STRING | LIST OF NUMBER`
  
negative.code: 
  == References
  
  * Wikipedia on https://en.wikipedia.org/wiki/Type_system[Type System]
  * CypherType and symbols package object in the Neo4j implementation
  * SPARQL and SQL standards
  
  