max
Largest float color-buffer precision that is render-target complete on this GL implementation. 32 =>GL_RGBA32F is renderable (desktop GL3+ / WebGL2 with EXT_color_buffer_float / Android+iOS-device GLES3 with the same extension); 16 => only GL_RGBA16F is renderable (some iOS Simulator GLES3 builds, GLES2 with EXT_color_buffer_half_float); 0 => no float color attachment is renderable and consumers must fall back to GL_RGBA8.
No engine consumer since the shadow and sightline pipelines moved to plain depth textures; retained as public capability API for applications that render their own float colour attachments.