An elegant triplet of fonts

An elegant triplet of fonts that go together
Type Font
Sans Serif PT Sans
Serif Gentium Book Plus
Monospace Monaco

I and l in sans-serif fonts

Many sans serif fonts fail to distinguish between uppercase I and lowercase l. Twitter's new font is an example of this.

On top of that, Twitter started dishing out blue ticks on subscriptions.

These two features combine to form deceptive Twitter usernames, as demonstrated

in this tweet by Adrian Roselli.

PT Sans passes this AppleTVPlus test.

This screenshot shows that PT Sans distinguishes between uppercase I and lowercase l by putting a tail on l.

But some famous fonts like Helvetica and Roboto fail at it.

This screenshot shows that Helvetica has identical looking uppercase I and lowercase l.
This screenshot shows that Roboto has identical looking uppercase I and lowercase l.