null (nil) value

Some parameters support the null value. The descriptions of these parameters indicate “nillable”.

"field_name": null
<field_name xsi:nil="true">

Resetting (clearing) a parameter

In the update and set methods, you can pass "null" to delete the value for such a parameter.

Getting a parameter

If a parameter is requested but its value is not set, the get method returns "null".