On this page: formulas in fields - formulas in the "visible" property

Formulas

Formulas in fields 

You can write formulas in the content of the field. This formula must start with =. You can use complex mathematic formulas.
Example:

=[Details].[unitprice]*[Details].[quantity]*(1-[Details].[discount])

The structure to get the content of the result of a field is:

[section name].[field name (result of the query)]

If the part "name of the section" is omitted then the field will be searched in the current section, in this case you can write: 

[field name (result of the query)]

Formulas in "visible" property

The visible property can accept formula. In this case you don't need to start the formula with =. The formula must produce a Boolean (true or false) result. In the field property you can also use the keyword "[me]" to use the value of the field itself in the formula. 
For example:

[me]<>0

The field will be shown only if its value is different than zero.