// This rule specifies whether non-capiltal 'l' can be
// used as a long value indicator. A non-capital 'l' can
// easily missread as a '1' (one). It is a good
// programming practice to just use 'L'.


...
// using a non-capital 'l'
doSomeCalculation(40l);
...

...
// using a capital 'L"
doSomeCalculation(40L);
...