Many people get emotional when it comes to the confusion of letters and digits.
You can’t criticize the 2018/19 Adidas font enough, but not necessarily for the confusion of letters and digits – simply because names only consist of letters (and punctuation) and numbers only consist of digits.
(What’s a big problem though is the confusion of letters and digits among themselves, but I'll treat this another time.)
Anyway, there are cases though where you don’t know if it’s about numbers or words:
Lately I had the pleasure of drawing a custom typeface for the German football club Mainz 05 as part of Done by People’s fantastic redesign.
In the initial draft, Done by People’s Dominik sketched a secondary club logo, and the client instantly loved it.
Usually a round part and an angular part make a five, so if your whole design idea avoids round shapes, it’s getting hard. Out of context, the angular shapes could be misleading: Is it “MOS” or “M05”?
In the final version of the club’s secondary logo the whole shape became more crest-like. And if you watch the five, you see that we added a little spur to the rescue:
Sometimes it’s the little things that make the difference!