Italics?

Greetings!

I just noticed that there is a shifting usage of italics in the formula
draft.

Compare:

6.8.22 IMSQRT - the N in syntax

versus

6.8.24 IMSUM - the N in syntax

Is there some reason why variables would be italic in one case and not
another? 

In the running text as well.

Hope everyone is having a great day!

Patrick