Understanding if

I believe I understand how to use if statements. However, I have a batch file that uses the following if statement

if %1.==. (
            Set iniFile=
            ) else (
            Set iniFile=--ini=%1
            )

This was written by someone else and I am trying to understand it and make a few changes. I do not understand the (.) before and after the == comparison. What is the significance of the (.)?