Returns the content of the object in which the calculation is defined.
Data type returned 
text, number, date, time, timestamp
The Self function provides a way for a calculation to reference the object with which it is associated without having to explicitly reference the object.
Use Self to create a single calculation formula that can be applied to different objects. The Self function is helpful for conditional formatting calculations and tooltip calculations because it returns the content of the layout object when that object has a value. You can also use the Self function in field definition calculations (including auto-enter and validation calculations) to return the value of the corresponding field.
self > 10 returns 1 (True) when applied to a layout field object whose value is greater than 10.
Related topics 
Functions reference (category list)
Functions reference (alphabetical list)
About formulas
About functions
Defining calculation fields
Using operators in formulas
Defining conditional formatting for layout objects