Looking at you, C++ STL. Almost nobody names structs/classes all lowercase. This leads to silly style guidelines eg. in the Google c++ style guide:
- Name classes PascalCase (even if it's templated)
- Except if your class happens to be a templated container type, in which case name it all lowercase.
In Python the logging library is written in camel case (as it was heavily based on log4j) unlike most of the rest of the standard library, but the developers have let it be because fixing it would break backwards compatibility, and in any case PEP 8 [1] says consistency within a module is more important than global consistency.
In my opinion they should have fixed it in the move from Python 2 to 3, but I guess they had enough headaches from that.
Case insensitive, of course
Postgres in particular has case-sensitivity quirks if you try to force the use of camelCase table names.