Technical details 
Continuing with the discussion in "Too technical" and "History" above: I envisage leaving in "Design and implementation" only the features that help a reader decide what SD is all about and what flavors there arethen renaming it "Features".  Sections that describe how it works ("File system", "Transfer modes", "Interface", "Power use", and "Storage capacity and incompatibilities") I'd move to a new section "Technical details" to occur afterward, even after the sections that describe the market acceptance and vendor-specific features.

The fact that the ability to plug an SD chip into an SD slot is impeded by several factors seems important to a lot of readers; I also appreciated knowing exactly what goes wrong, and the exact history, but these are also "Technical details".  I'll volunteer for the editing, but will instead focus on nits for a few days to await youse's responses.