To customize your filenames even further you can use tags. Tags are used to get known information about the files. "But how does it work?" All text you write will be used as filename except for all the text in <'s and >'s. If you write something like "file_<name>" and renames a file called "notepad.exe", the result will be "file_notepad".
You can use both tags and regular text in most text boxes in Advanced Renamer. Tags are most used in the New Name Method but can be used in almost all the other methods. You can right click in a text box, and if you see the item "Insert Tag", you can use tags. Click it and you will get a window with all tags.