@michal I used a manual typewriter all through college. And I don't recall ever having a problem distinguishing what that <lowercase L> character was being used for. The context was always clear. On the web, I *constantly* have that problem. I examine one font really closely, and <lower l>, <num 1>, and <cap i> were _identical_. I think, perhaps, writers were aware of this and would rewrite to make it clear.

Fonts should have serifs for readability.