https://voxelmanip.se/2024/12/14/sdl-lean-and-mean/
An article on a mostly-undocumented #libSDL option.

SDL_LEAN_AND_MEAN
As storage space becomes larger and larger even on the most modest of phones and bandwidth is becoming evermore plentiful, software tends to become larger in size over time as the necessity to optimise filesizes decreases. But there are also people who wish to reverse the trend by trying to conserve the amount of space their resulting program becomes through going closer to the metal or finding clever ways to cut down the size of their dependencies. SDL is a library that aims to provide cross-platform low level access to input, audio, graphics and more that will just work across all supported platforms, for games and other multimedia programs. While the library originally had humble beginnings it has since grown with size as new features that while may be useful to some, are not something everyone would utilise when using SDL. Thankfully there are countless build options you can use to control what gets built with SDL but there is also the rather funnily named and undocumented define, by the name of SDL_LEAN_AND_MEAN.