Validation in Draft 4 and below
The 'exclusiveMaximum' keyword must is a boolean.
If "exclusiveMaximum" is not present, or has boolean value false, then the instance is valid if it is lower than, or equal to, the value of "maximum";
If "exclusiveMaximum" has boolean value true, the instance is valid if it is strictly lower than the value of "maximum".
If "exclusiveMaximum" is present, "maximum" MUST also be present.
Its default is false.
Validation in Draft 6 and above
The value of "exclusiveMaximum" MUST be number, representing an exclusive upper limit for a numeric instance.
If the instance is a number, then the instance is valid only if it has a value strictly less than (not equal to) "exclusiveMaximum".
Graphical Representation
The constraint is represented in line within the diagram, properties with the icon 
apply to instance array values.
Constraints are also shown in the property grid when the containing schema is selected.
If the schema is not allowed to contain an array value, then the constraint is ignored and not shown in the property grid.
The constraint values are also shown on the tooltips (select and hover over an item in the diagram).
Editing
Its value can be edited in the following ways
- In place on the schema object by expanding the properties and clicking on it once it is already selected.
- Edited via the properties window when the containing schema is selected
- Edited directly in the Json Source view.
It can be deleted by selecting it and pressing delete, or right clicking it an pressing delete.