Lingala is a language spoken in both the Democratic Republic of the Congo and in the Republic of Congo by some 2.1 million people. This language uses the Latin script for its writing and has some additional characters. Two examples are found in "nyɔ́nsɔ" and "Kɛndɛ"́. Sadly not all fonts show these characters correctly.
In order to fix this problem, in the CSS of the Lingala Wikipedia some changes have been added indicating what fonts show these characters correctly. Given that the purpose of pro
jects like Commons, Meta and Betawiki is to support all languages properly, I would suggest that it makes sense to adopt these changes on a wider scale.