C# ma ostrzegać jak mu sie nazwa typu nie spodoba, czyli jak użyjesz samych małych liter.
C# 11 is the next version of C# coming in .NET 7, and it is introducing a warning wave that issues a warning when a type is declared with all lower-case letters. This is being done so that in the future the language can begin moving away from conditional keywords and instead use full on keywords instead. The warning is alerting customers to types that may become keywords in future versions.
https://blog.paranoidcoding.com/2022/04/11/lowercase-type-names.html